Andy Coulson, the prime minister’s former spin doctor, is being investigated by police for allegedly committing perjury while working for David Cameron in Downing Street.
This is the third criminal investigation Coulson faces.
He is also accused of knowing about phone hacking while editing the News of the World and authorising bribes to police officers.
The latest inquiry centres on evidence Coulson gave in court last year that led to socialist Tommy Sheridan being jailed.
Coulson was a major witness in a trial involving Sheridan.
The former MSP was accused of lying in court when he won a libel action against the News of the World.
Coulson had been the editor of the Sunday tabloid when it ran stories on Sheridan’s personal life.
Coulson denied any knowledge of phone hacking and payments to police officers at the Sheridan trial.
At the trial Coulson also denied knowing that the paper paid police officers for tip-offs.
This contradicts recent disclosures that News International has uncovered emails showing that payments were made to the police during his editorship.
Sheridan was found guilty of perjury and jailed for three years in January.
Bob Bird, the News of the World’s Scottish editor, and Douglas Wight, the Scottish edition’s former news editor, also gave evidence.
Sheridan’s lawyer, Aamer Anwar, said, “Over two weeks ago we provided a detailed dossier of allegations of perjury, phone hacking and breach of data to Strathclyde police and called for a robust investigation.
“Over £2 million was spent by the police on investigating Mr and Mrs Sheridan and we were told it was in the public interest.
“I expect now to see a similar ruthlessness and determination in dealing with the News of the World.”
For background on Tommy Sheridan’s case go to www.socialistworker.co.uk//art.php?id=23459