The Police Service of Northern Ireland (PSNI) was tonight under intense pressure to explain how a gang of robbers broke into the anti-terror unit of a Belfast police station and assaulted an officer.
A major investigation into the raid on the special branch office in the east of the city was continuing, with senior officers sworn to secrecy until the probe is completed.
Police have refused to confirm if any documents were stolen, but it is thought a notebook may have been taken by intruders who burst into the Castlereagh complex.
The security breach left Belfast Lord Mayor Mr Jim Rodgers in no doubt that the culprits had intimate knowledge of the station's lay-out.
He insisted: "The whole thing stinks to high heaven."
After they infiltrated the police base last night, a lone officer in the special branch section on the first floor was attacked.
He was tied up following a struggle before the gang made their getaway.
"The entire area around the office has been sealed off and a meticulous forensic examination which will take some considerable time is under way," said a spokesman for the PSNI.
Police are also combing the whole station for clues.
The spokesman added: "Until this is completed it's not possible to state whether documentation or other material has been taken."
Chief Constable Sir Ronnie Flanagan today held urgent talks with senior officers in a bid to get to the bottom of the breach.
Special branch sources, who have been ordered not to talk about the case, indicated it could be some time before the investigation discovered if anything had been taken.
Although he refused to comment on the break-in, one said: "Because of the forensic examination that's going on we are not sure if anything has been stolen. It could take a couple of days."
Mr Sammy Wilson, a Democratic Unionist member of the Northern Ireland Policing Board, was stunned by the break-in.
"This is absolutely amazing and extremely embarrassing," the East Belfast MLA said.
Mr Wilson said he has been inside Castlereagh on numerous occasions on official duties and pointed out officers were always present to check on those coming through the front doors.
"The police have a lot of explaining to do regarding the security at Castlereagh," he added.
"Having gone in and out of the station I can't see that it's that easy to walk in.
"Members of the public shouldn't get through until they state what their business is."
Mr Rodgers claimed paramilitaries gangs could not be blamed. "Not for one moment do I believe that either a republican or loyalist organisation has been responsible," the UUP councillor said.
"It's someone who knows something about the workings of Castlereagh and the lay-out."
The Lord Mayor also drew comparisons with a mysterious fire at another Northern Ireland police station which destroyed files on alleged security force collusion with loyalist terrorists.
The blaze caused extensive damage to offices used by Metropolitan Police Commissioner Sir John Stevens' team during their ongoing probe.
"People are going to ask deep and searching questions," Mr Rodgers insisted.
A spokesman for Northern Ireland police ombudsman Mrs Nuala O'Loan said she would not be getting involved in the probe.
He added: "We are watching it to see how it develops."
PA