A former editor of the News of the World Scotland has been arrested and charged with attempting to pervert the course of justice at the time of ex-MSP Tommy Sheridan's defamation action against the newspaper.
Bob Bird was detained in Glasgow this morning by officers from Strathclyde Police.
He has since been released from custody and a report will now be prepared for prosecutors.
A force spokewoman said: "Officers from Operation Rubicon of Strathclyde Police arrested and charged a 56-year-old man with attempting to pervert the course of justice at the time of the defamation action of Thomas Sheridan versus News Groups Newspapers.
"A report will be submitted to the procurator fiscal in Glasgow.
"Proceedings are now active and it would be inappropriate for us to comment any further."
Bird was held and questioned at Govan police station before being charged. It is thought he was detained at about 7.30am and arrested about four hours later.
The charge centres around Sheridan's defamation action against the News of the World six years ago.
The former socialist MSP won his civil case against the Sunday tabloid at the Court of Session in Edinburgh in 2006, winning damages of £200,000 over claims about his private life.
But in January last year Sheridan was jailed for three years after being convicted of lying about the now-defunct tabloid's claims. He was released from jail after serving one year of his sentence.
Bird gave evidence at the 2006 libel case and at the perjury trial.
Less than a fortnight ago, a former news editor of the News of the World Scotland was arrested and charged with committing perjury during Sheridan's 2010 trial, and with conspiracy to hack telephones.
Douglas Wight, 39, also faced allegations of other data protection offences following an investigation by Rubicon officers.
In May, Prime Minister David Cameron's former communications chief Andy Coulson was arrested and charged with committing perjury at the same trial.
The ex-News of the World editor, who gave evidence at the High Court in Glasgow in December 2010, said he would "vigorously contest" the allegations.
Sheridan's solicitor Gordon Dangerfield said: "Today's arrest is the latest in a series arising out of the Tommy Sheridan cases.
"It would not be right to comment on individual charges but, as we have always said, there was a serious and wide-ranging criminal conspiracy against Tommy Sheridan in these cases.
"We look forward to the whole truth coming out in court at last."
Operation Rubicon is the Strathclyde Police inquiry into allegations of phone hacking, breach of data protection and perjury.
Under Rubicon, officers from the major investigation teams were tasked by the Crown Office to examine aspects of the evidence presented during the 2010 Sheridan perjury trial.
In addition, they are also examining specific claims of phone hacking and breaches of data protection in Scotland.
In Scotland, a person can be detained for up to 12 hours before being arrested or released. In certain cases, police can apply for that time limit to be extended.