Andy Coulson, David Cameron's former director of communications, has been detained by police investigating alleged perjury at the trial of the Scottish socialist politician Tommy Sheridan.

Strathclyde police said Coulson was detained in London on Wednesday morning for questioning in connection with evidence the former News of the World editor gave during Sheridan's own trial for perjury in December 2010.

It is understood that Coulson was visited unannounced at his home in London at 6.30am by seven Strathclyde police officers before being driven to Glasgow under escort. He was taken to Govan police station, the base for Operation Rubicon, the inquiry set up to investigate alleged perjury at the trial.

He arrived at 3.30pm, and can be questioned for up to 12 hours from his arrival. The police can then either release him, charge him or ask a senior officer for authority to hold and question him for another 12 hours.

Coulson, who was at the time serving as the prime minister's chief media adviser at 10 Downing Street, was called as a defence witness by Sheridan, who was on trial for lying in court when he won a £200,000 defamation action against the NoW.

The former NoW editor was questioned over two days at the high court in Glasgow by Sheridan, who conducted his own defence, about his knowledge of a hacking operation against Sheridan carried out by Glenn Mulcaire.

During the trial, Sheridan produced documentary evidence that he had been twice targeted by Mulcaire, a private detective hired by the NoW, in 2004.

It has since emerged that other close members of Sheridan's family and associates were also named and potentially targeted by Mulcaire, including the politician's mother, Alice Sheridan, and the Scottish politician Joan McAlpine, a former friend of his who co-wrote a book on Sheridan's anti-poll tax campaign in the early 1990s.

Strathclyde police, in tandem with senior prosecutors at the Crown Office, Scotland's prosecution authority, launched an inquiry into alleged perjury at Sheridan's trial and into hacking in Scotland last autumn. The investigation, Operation Rubicon, involved at least 50 detectives.

Under Scottish police procedure, Coulson has not been formally arrested as he has not yet been charged. This is the second time he has been detained in connection with the wider hacking affair: he has already been arrested by the Metropolitan police as part of its investigations into NI.

In a brief statement, a Strathclyde police spokeswoman said: "I can confirm officers from Strathclyde police's Operation Rubicon team detained a 44-year-old man in London this morning.

"It is under section 14 of the Criminal Procedure (Scotland) Act 1995 on suspicion of committing perjury before the high court in Glasgow."

Sheridan was convicted by a majority verdict at the high court in December 2010 over his evidence relating to lying to former colleagues in the Scottish Socialist party about his private life when he sued the NoW in 2006 for libel over allegations about his sex life.

The jury at that libel hearing at the court of session in Edinburgh found in Sheridan's favour, and the then Scottish Socialist party leader was awarded £200,000 in damages.

Payment of those damages has been delayed after NI appealed against the verdict; that case has been suspended pending the outcome of Operation Rubicon investigation.