Larry Zaitschek currently lives in the United States
Chief Constable Sir Hugh Orde has said he is frustrated that the case against Larry Zaitschek collapsed.
Police were planning to bring him to trial over the break-in at police headquarters at Castlereagh in 2002, when special branch files were stolen.
Mr Zaitschek had worked as a chef at the base.
However, last week police said they could not disclose all relevant material and conceded he would not receive a fair trial.
Mr Zaitschek has always denied all the charges against him and denied having anything to do with the break-in.
He has been living in the United States since shortly after the raid.
Sir Hugh Orde said he was disappointed the case against him had to be pulled after seven and half years of investigation.
"There is nothing within my intelligence systems that I was not prepared to release to enable a fair trial to take place," he said.
"So there's a clue in that, the issues that arose were outwith my jurisdiction and I will not have my service criticised for something that was out with my responsibility, I think that would be very unfair."
The incident at the Castlereagh security base on 17 March 2002, was a huge embarrassment for the police.
Three men walked into what was supposed to be a highly secure room packed full of sensitive security information, tied up a police officer and stole dozens of Special Branch files.
These files included details of Special Branch officers and their agents' codewords.
Millions of pounds were spent re-housing officers and others, whose security had been compromised.
Mr Zaitschek flew to the US shortly after the break-in, leaving his wife and young son behind.
It is understood that Mr Zaitschek's wife was in protective custody after the incident and may have been used as one of the key prosecution witnesses.