FORMER top detective Ray Mallon claimed last night that the audacious theft of his £40,000 mayoral chain of office was an "inside job".

The man who pioneered zero tolerance policing swiftly dusted down his detective's badge and has already come up with "one clear suspect" within the corridors of Middlesbrough Town Hall.

Mr Mallon is convinced the theft of the nine-carat gold chain was calculated to both undermine his position as Middlesbrough's first directly-elected mayor and embarrass the borough council.

The chain - which is made up of 30 kite-shaped links - disappeared last week as Mr Mallon was at a town hall function.

Guests included the Lord Lieutenant, High Sheriff, mayors and senior council figures - whom the former detective superintendent has already ruled out of the frame.

"By doing a little bit of detective work I have come to the worrying conclusion that the theft of the mayoral chain was an inside job rather than that of a sneak thief," said the former head of Middlesbrough CID.

"By applying the basics of offender profiling, I have narrowed down the suspects even further to the point that, in my own mind, there is one clear suspect who stands above all others.

"I believe the thief has a direct link with the local authority and knew the backstage area of the town hall. We can rule out the Lord Lieutenant, High Sheriff and front-of-house guests."

Mr Mallon wore the chain of office for only a minute for a backstage photograph following the installation of the council's new chairman, Peter Porley, and his deputy, Javed Ismail.

The chains were then placed in a bag and left unattended in the robing room while Mr Mallon returned to the main auditorium during last Wednesday's ceremony.

The chain was stolen sometime between noon and about 2pm, when the bag was found to be missing.

"Within hours of the disappearance, the media were informed in detail of the chain of events - in fact they knew about the theft before I did and that is an important factor," he said.

"It was an inside job, the target chosen to embarrass either myself or the council or, most likely, both.

"Of course, there is a degree of dark humour about it because I'm the man who's determined to clamp down on crime."

He said his first thought was that the chains may have been misplaced or hidden, but two detailed searches failed to uncover anything.

Mr Mallon has also ruled out the involvement of a sneak thief, who he says, would have had to overcome tight security, would probably have been seen by caterers and other staff and would have needed a detailed knowledge of the building.

"A sneak thief would have no idea that the chain would be left unattended in that particular location, but there is no evidence to suggest other rooms on route had been searched.

"In addition the only thing taken from the robing rooms was the chain, a closed briefcase on a table nearby was untouched."

He added that the distinctive chain would be almost impossible to sell on and melting it down would vastly reduce its value.

"Whoever took the chain knew exactly where it was and wasn't interested in anything else. The motive wasn't financial nor was it an ill-judged prank."

"I don't feel embarrassed about what has happened but I do feel sad that the chain, which is a part of Teesside's heritage, may never be seen again.

"The saddest aspect of this whole episode is that, if my theory of an inside job is correct, the thief has sought to bring ridicule upon the proud town of Middlesbrough he is supposed to serve.

"He has tried to undermine the excellent work being carried out by councillors and employees - he will not succeed."

"I have every faith in Middlesbrough police to investigate this matter thoroughly. It is easy for me to theorise but gathering enough evidence to charge will not be easy.

"I would, therefore, urge the public to come forward with any information they have."

A spokesman for Cleveland Police said that the theft was still under investigation. Anyone with information can call them on (01642) 303126