Ron McKay, 46, a reporter for the Scotland on Sunday newspaper, was arrested in Chatham, Kent, by officers from the Lothian and Borders Police.
Andrew Jaspan, the paper's editor, said Mr McKay had been charged with reset - called receiving in England - which is the receiving of stolen property or being privy to its retention.
Mr McKay had disclosed details of a break-in 11 days ago at police headquarters in Fettes Row, Edinburgh, during which dozens of files relating to anti-terrorist operations, drug surveillance and the Animal Liberation Front (ALF) were stolen.
Scotland on Sunday carried a report on the files last weekend. Mr McKay, who was working at the paper's Glasgow office, had apparently been contacted by a man codenamed Hector, who showed him photocopies of the reports.
Mr McKay's contact said the break-in was carried out by ALF members working with criminals. Part of the deal, the newspaper said, was for relevant files on drug operations and other matters to be handed to the criminals.
ALF information was retained by them and details of Irish anti-terrorist activities were passed on to republican and loyalist sympathisers.
Mr Jaspan said Scotland on Sunday had carried the story 'as a matter of grave public concern'.
He said: 'The files removed from the headquarters contained highly sensitive information, including the names of informers. The ALF said it had issued warnings to those people.
'We had agreed to co-operate with the police but did not expect a member of staff to be arrested.'
He added: 'I understand there is also considerable concern within the ranks of officers at the poor security at the police headquarters.'
The ALF claimed to have entered the police HQ twice to remove holdalls full of documents. 'Hector' said some files had been destroyed and others buried - for 'insurance in the future'.
One file shown to the newspaper was said to be of a police operation involving phone-tapping at Lothian regional council offices, government offices, Edinburgh pubs, the offices of a lawyer, and Jenners department store in the city's Princes Street.
Alistair Darling, MP for Edinburgh Central, was due to raise the arrest with Sir William Sutherland, the Chief Constable of Lothian and Borders, at a meeting in Edinburgh yesterday.
Police would not confirm details except to say that a man had been arrested.Reuse content