Spy author Robert Harris believes a thief who stole a computer hard-drive from his house may have been looking for information about his friend Peter Mandelson.
Mr Harris's Berkshire home has been swept for listening devices after the suspicious break-in just days after the former Northern Ireland Secretary announced his resignation.
The hard-drive was the only thing stolen over the weekend of February 10. The raid happened just over two weeks after Mr Mandelson's resignation. The MP for Hartlepool is rumoured too be taking refuge at Mr Harris's house.
Police have questioned the motive for the burglary after an expensive watch, television and video recorder were left untouched and no fingerprints were found.
One theory is that the raid was orchestrated by the security services in a bid to keep track of Mr Mandelson as he fights to clear his name. Mr Harris said the mystery thief might have thought that Mr Mandelson had been using the computer.
Mr Harris, the author of Fatherland and Enigma, said Mr Mandelson had been "shocked" to hear of the theft from the cottage in Kintbury, near Hungerford.
He added: "Whoever did it jemmied a window and were in and out. It was the way they disconnected the mouse and keyboard and everything - it was almost comic.
"An ordinary thief would have stolen it all. CID said they had never seen anything like it. They would think Peter had been in touch with me, that he might have been working on the computer and might have written notes on it.
"It's strange that burglars should arrive, stealing only my computer disc, at a time when everyone was after Peter."
Mr Harris, who has been highly critical of Downing Street's treatment of Mr Mandelson, said it seemed his telephone calls could also have been bugged.