Security companies and private detective agencies are among the businesses benefiting from employers' more rigorous approach to checking and cross- checking job applicants' credentials.
Chief among the fears of employers about prospective employees is the risk of paedophiles being employed as childcare workers, convicted burglars hired as security guards, and fraudsters working with money
Just as employers have turned turned to vetting agencies, so too has the Government started to encourage extra vigilance. It plans to set up an agency to vet security guards and to make employers responsible for ensuring that they do not hire illegal immigrants.
However, civil-rights groups have warned that people could be treated unfairly on the basis of information acquired by vetting.
Vetters check potential employees in a variety of ways, such as requiring applicants to fill in special application forms with questions such as whether the job seeker has ever been in court as a defendant, to informal chats. Checks are also made on the authenticity of qualifications listed.
"We had to turn down 40 per cent of the people who applied for a job with one of our clients," said Martin Samociuk, chief executive of Network Security Management
Gaps in a job applicant's career history are the kind of clues that set prospective employers' alarm bells ringing. Network Security Management was called in to check one job applicant when he explained a two-year hole in his CV by writing: "A period of surgical operations and convalescence."
The vetters discovered that the applicant had in fact been in prison during those two years. He was rejected for the post.
"This is very much a growth business," said Andrew Fisher, a senior consultant at Network Security Management. "The number of screenings we have done has multiplied by 10 in the past 18 months and we expect that rate of growth to continue."
Another company, Equifax, which sells credit and business information to companies, can also provide them with information about their own staff and job applicants. Equifax uses data gleaned from public records including County Courts and the electoral roll.
Demand for vetting services at the top end of the market is such that companies are charging pounds 1,000 a day.
"Many companies are waking up to the need for vetting," says John Conyngham, head of international investigations at security firm Control Risks. "Recent fraud surveys have shown that the greatest risk that companies face is from their own employees."
Some civil-rights groups and personnel management experts, however, have their doubts about the vetting boom.
"I can't see any reason for doing most of it whatsoever," says Angela Baron, policy adviser at the Institute of Personnel and Development. "Companies should only take into account work-related criteria.
"If you ask for a subjective view about whether someone can do a job, the people you ask want to know your company or your job requirements and it's very unlikely that we would recommend something like taking routine credit references.
"Otherwise you are making certain assumptions about people - for example, that if they are in debt they are more likely to steal from you. Fraud convictions show that this doesn't stack up."
But the vetting companies take a robust view to this and other objections. JohnSimpson, managing director of Personnel Vetting Services, said: "A lot of people are concerned about civil liberties being infringed but the bottom line is that if you have nothing to hide you have nothing to fear."
However, John Wadham, director of the civil-rights group Liberty, warned that while vetting may be necessary in some cases, its procedures must be transparent.
He said: "All people involved must know that it's going on. Information must be on the table so that if there are any inaccuracies they can be corrected."