The head of the agency that vets security staff quit yesterday after it emerged that he could not be sure that some of the agency’s own workers had proper clearance.

Mike Wilson left his £94,000 job as chief executive of the Security Industry Authority after a Home Office review found 38 staff processing applications for security licences had not been vetted themselves.

It is the second embarrassing failure in less than a year to undermine the watchdog’s reputation. Last year thousands of illegal immigrants were found to have been given licences to work as security staff. Some had jobs at Whitehall departments, with one a security official at the Home Office and another guarding the Prime Minister’s car while it was being repaired.

The latest blunder came to light on October 29 during a Home Office review prompted by concerns over the body’s management. Staff handling sensitive data, including Criminal Records Bureau checks, are supposed to have enhanced clearance.

In a written Commons statement Alan Campbell, a junior Home Office Minister, admitted that the body had failed to check whether 38 temporary workers hired to clear a backlog had the correct clearance. Mr Campbell said the staff had been “removed from SIA premises” while security checks were carried out.

The Tories accused Jacqui Smith, the Home Secretary, of seeking to slip out bad news and evade responsibility for the Security Industry Authority’s failure. Dominic Grieve, the Shadow Home Secretary, said: “Yet again an official takes responsibility while the minister ducks it.”

Mr Wilson’s departure came after growing concern in the Home Office over the authority’s direction. One senior figure said that the failure to vet agency staff properly was the “straw that broke the camel’s back”. Mr Wilson joined the authority last year and is expected to get a payoff.

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