After he moved to France at the end of last year, an official source said that operatives had been monitoring his moves. "There was no difficulty posed by trying to find him. I don't think there was ever a problem vis a vis 'Where is David Shayler'," said the source.
Mr Shayler, 32, was arrested at 8pm on Saturday evening in Paris after returning to his hotel from a bar where he had been watching his favourite team, Middlesbrough, playing at home to Newcastle.
At his hotel, the Golden Tulip in St Germain, Mr Shayler was met by members of the Direction de la Surveillance de Territoir - the French equivalent of the Special Branch. After questioning at the Ministry of the Interior he was taken to the Prison de la Sante.
Mr Shayler had travelled to Paris from a cottage in rural France where he had been living with his girlfriend - Annie Machon, herself a former MI5 officer.
He was in Paris to record an interview for the BBC's Breakfast with Frost programme to be broadcast the following morning.
He was also meeting a reporter from the Mail on Sunday, the paper to which he originally sold his revelations last year for pounds 40,000.
Adding to the intrigue was the presence of Richard Tomlinson - a former MI6 officer who served a 12-month prison sentence for breaching the Official Secrets Act.
Mr Tomlinson, a former SAS officer who was arrested by French security police hours before Mr Shayler, had been talking to reporters from another Sunday newspaper. He had earlier been speaking to Ms Machon by telephone and it is understood that at some point during the weekend he may also have spoken to Mr Shayler.
There was speculation last night that security officers may have been alerted to Mr Shayler's whereabouts by intercepting phone calls he was making to reporters.
The BBC said last night the Frost team were speaking to Mr Shayler by mobile phone but that they were not aware where he was staying.
"The location for the interview had still to be arranged when he was arrested," said a spokesman.
"I do not think we knew where he was staying. Even if people had intercepted the calls they would not have heard anything of any use," he said.
The claim that Mr Shayler had been under surveillance for many months holds credence.
The French authorities would have been well aware of Mr Shayler's self- imposed exile in France and several officers from MI6 - the foreign intelligence service - are attached to the British Embassy in Paris.
The Home Office denied Mr Shayler's arrest was due to revelations that were to be made in the weekend's newspapers.Reuse content