Responsibility for the UK's second largest E.coli outbreak falls squarely on the shoulders of one butcher, the chairman of the public inquiry said today.

Professor Hugh Pennington said William Tudor had "a significant disregard for food safety" which led to 157 cases of E.coli including the death of a five-year-old boy in 2005.

The professor said inspections by environmental health officers in Bridgend, south Wales, were made less effective by Tudor's dishonesty.

But he said the inspectors missed clues about the business's management of food safety.

He added the Meat Hygiene Service allowed the abattoir supplying Tudor to continue functioning despite knowledge of its failures.

The professor made 24 recommendations in a bid to prevent a repeat of the outbreak which affected 44 schools in the south Wales valleys.

He said the food safety regulations in force at the time of the outbreak were sufficient and his recommendations reflected what he believed needed to be improved, tightened up or reinforced.

Mason Jones, aged five, died in October 2005 after contracting the 0157 strain of the bug.

Butcher Tudor, of Clemenstone, Cowbridge, was jailed for 12 months in September 2007 after admitting placing unsafe food on the market and failing as proprietor of a business to protect food against the risk of contamination.

Professor Pennington said: "We owe it to the memory of Mason Jones to learn the lessons from this outbreak and to remember them."

Prof. Pennington said: "The outbreak occurred because of food hygiene failures at the premises of John Tudor and Son. The proprietor, William Tudor, failed to ensure that critical procedures, such as cleaning and the separation of raw and cooked meat, were carried out effectively.

"He also falsified certain records that were an important part of food safety practice. On some issues, he misled and lied to environmental health officers."

He said the business's Hazard Analysis Critical Control Point (HACCP) plan was not valid and added: "In some respects it was positively inaccurate and misleading."

Prof. Pennington said the likelihood of meat becoming contaminated with E.coli at the abattoir of JE Tudor and Son, would have been significantly reduced if the meat hygiene regulations had been followed and enforced.

He said the path to infection in the majority of cases in the outbreak was contaminated cold cooked meat that had been supplied for school meals.

Schools were supplied with meat by John Tudor and Son under a contract with the Rhondda Cynon Taf, Bridgend, Caerphilly and Merthyr Tydfil County Borough councils.

The professor said the process by which the contracts were awarded in 1998 and 2002 was seriously flawed.

He added that outbreak control was done well by all involved.

He said: "I had hoped that the lessons from the shocking events in Scotland in 1996 would stay in people's minds but some 10 years after leading a review into that outbreak, I have found myself looking at issues that are disappointingly all too familiar."

He recommended that all food businesses ensure their systems and procedures are capable of preventing contamination or cross-contamination with E.coli 0157.

He said: "E.coli 0157 is a real threat. There is no room for complacency. It will exploit weaknesses and failures in hygiene practices be they down to a lack of knowledge, sloppiness, or even downright indifference to the risk."

He said he was recommending additional resources be made available to ensure all food businesses in Wales understand and use the HACCP approach and have in place an effective food management system that is embedded in their working practice.

He said his recommendations also reflected the need to improve inspection practices.

"Issues and concerns must be logged so that they are not lost when inspections are undertaken by different officers," he said.

The professor added the "light touch" enforcement regime applied by inspectors in Tudor's case had its place but should not be allowed to simply roll on.

He said the four authorities involved in the outbreak had all made substantial changes to their procurement systems and procedures.

He said: "However, I am recommending that all businesses contracting with public bodies for the supply of high risk food such as raw and cooked meat must be subject to independent food hygiene audits."

He said he was asking the National Assembly for Wales to monitor and report progress on implementation of his recommendations.

He said: "I am recommending that a substantial review of food hygiene enforcement in Wales should take place in approximately five years' time."

Speaking after the release of the report, Mason's mother Sharon Mills thanked the inquiry team for their in-depth investigation.

She said she was glad it was brought to the public's attention "the systematic failures from farm to fork".

Ms Mills, 34, said the report reinforced her belief that Tudor was responsible for her son's death.

She said: "I believe the inspection regimes clearly should be tightened. There is no excuse for the serious failings which occurred which ultimately led to the E.coli outbreak."

She added: "Abattoirs' reliance on self regulation leads to business owners cutting corners which is what has led to the tragedy such as E.coli outbreaks.

"I agree that all businesses that are dealing with raw and cooked meats need to have in place an effective HACCP plan."

Ms Mills said: "Professor Pennington has come to the conclusion William Tudor is to blame for the E.coli outbreak that killed our five-year-old son and we now look to move on to the inquest into our son's death where we hope the coroner will reach an appropriate verdict.

"On Mother's Day 2014 I don't want to be standing here sympathising with another family that has lost a child from E.coli 0157."

She said she was not confident at this time that the professor's recommendations would be implemented but she was determined to make sure that they were.

She added she would be campaigning for tougher prison sentences for breaches of the hygiene regulations.

She said: "I miss Mason dearly, I would do anything to have him back because he was a great kid and he suffered greatly from E.coli.

"I just want people to know how bad this bacterium is and how powerless I felt standing by the side of him watching him die from it.

"It's a terrible, terrible horrendous bacterium. I think people should be made more aware of it."

Bridgend County Borough Council welcomed the report and said it had co-operated fully with the public inquiry.

Andrew Jolley, the council's assistant chief executive for legal and regulatory services, said: "The public can be assured that the authority will do everything it can to ensure food safety.

"However, we should not forget that William Tudor deliberately misled and deceived our officers during the course of their inspections and showed a significant disregard for food safety."

Council leader Mel Nott said: "I would also like to express my personal sympathy to everyone affected by the E.coli outbreak of 2005.

"It was a deeply difficult time for all the families concerned, not least the family of Mason Jones who have had to endure so much.

"I know I speak for the whole of Bridgend County Borough Council when I say how committed we are to providing a rigorous food inspection service.

"I'm encouraged that many of Professor Pennnington's recommendations for improvement are already in place here and the public can be assured that their health and safety is of paramount importance to this authority."

In a statement, Rhondda Cynon Taf County Borough Council said it had made "significant improvements to the processes and procedures for the procurement of food for our schools".

"We have made sure that every reasonable measure has been taken to protect public safety in the delivery of our services.

"Given the actions that the council has taken following the outbreak we can confidently reassure our residents that the services we provide are delivered to the highest possible quality and standards."

A statement from the families of those affected by the outbreak said: "During the past three-and-a-half years, we and our children have had to come to terms with the lifelong impact of this terrible event.

"During Professor Pennington's inquiry, we found out in great detail how this terrible outbreak occurred.

"We were shocked and appalled at everything that came out as we had not realised the full extent of the problems and how long they had been going on for.

"We believe that Professor Pennington's report has identified the extent of the problems that allowed the outbreak of September 2005 to occur and has addressed many of our concerns.

"We are pleased he has concluded that the blame for the outbreak falls squarely on the shoulders of William Tudor as that is clearly the position, but he has also identified mistakes and failings particularly in inspections and procurement that could have avoided the outbreak."

Stephen Webber, the lawyer who has represented the families throughout, said: "We have always had every confidence in Professor Pennington and recognise how thorough and comprehensive his investigation has been, but how can we be sure that his recommendations will be implemented to stop this ever happening again?

"Unfortunately, this report has no legal power to ensure compliance with the recommendations and therefore it is of vital importance that the public authorities not only heed the recommendations but implement them as a matter of urgency.

"We appeal to all the public authorities involved in food production to take immediate action on the report's key recommendations.

"In particular the Welsh Assembly Government should heed the recommendation for them to monitor and report on implementation as well as hold a substantial review in five years' time."

The Food Standards Agency said it would review today's report in detail.

In a statement, it said: "The outbreak of E.coli in Wales in 2005 was a grave, but unusual, event and the report of the independent public inquiry is valuable in understanding the chain of events that led to the outbreak.

"Everyone involved in the production and distribution of food has a role to play in ensuring food safety - from food producers to people in their homes. When rare outbreaks such as this occur we must learn from them and further strengthen our systems."