The police force investigating the suspected murder of missing chef Claudia Lawrence said today it was disappointed by criticisms about the "thorough, professional and challenging" inquiry.
North Yorkshire Police said it had received no complaints about attitudes in the force after a statement released by a friend of Miss Lawrence's father claimed some staff members were "rude" and "dismissive" to members of the public phoning with information.
The statement, released by Martin Dales, a friend and spokesman of Peter Lawrence, called for an urgent independent inquiry into the police investigation.
Mr Dales said in the statement: "I have received numerous communications from both public and media via findclaudia.co.uk over the last 13 months which I have always passed on to the police.
"Many of them have found that when they phone the police, attitudes towards them are, amongst other things, 'uncivil, rude, abrupt and dismissive', to quote a recent report to the police authority."
He added: "What is really needed now is an urgent independent inquiry with a public report. Nothing less will do and transparency is vital if trust is to be restored in North Yorkshire Police."
Mr Dales said he was still waiting for responses to emails he sent to the police authority detailing public concerns about the investigation and a further email sent to the incident room including possible new information about the case.
North Yorkshire Police today announced it had voluntarily requested a further review of the investigation by the National Policing Improvement Agency (NPIA).
Responding to Mr Dales' comments, Chief Superintendent Iain Spittal, chief of staff for North Yorkshire Police, said: "North Yorkshire Police is disappointed by the comments made by Mr Dales, particularly as they had not been sanctioned by Mr Lawrence or any other member of Claudia's family prior to release, nor do they reflect Mr Lawrence's views.
"The investigation has, and continues to be, a thorough, professional but challenging inquiry.
"Many calls have been made to the incident room over the course of the past year and thousands of lines of inquiries developed. Due to the volume, it is not always possible to provide feedback on every call.
"Mr Lawrence has recently been personally briefed by the senior investigating officer and expressed his satisfaction over the conduct and progress of the investigation.
"We pride ourselves on good practice and seek to continually improve our service to our communities, which is why we have sought a further review by the National Policing Improvement Agency."
Mr Spittal continued: "We have not received any complaints regarding incivility or rudeness of the staff working on the investigation. One complaint regarding one of hundreds of searches was received but not in relation to incivility.
"If Mr Dales wishes to impart the names of the concerned members of the public to the force, we will look into the complaints he refers to."
Jeremy Holderness, chief executive of the police authority, added: "North Yorkshire Police Authority are exercising appropriate scrutiny on behalf of the public through updates given by the investigation team and are satisfied in the processes being undertaken."
Miss Lawrence, who was 35 at the time of her disappearance, was last seen near her home in Heworth, York, on March 18, 2009, and failed to arrive for her job as a chef at the University of York the following morning.
An initial review of the police investigation into her disappearance was carried out by the NPIA last year.
North Yorkshire Police said at the time that the results were "extremely positive" and the force was acting upon a list of recommendations.