Police leading a perjury investigation today questioned the wife and father-in-law of former Scottish Socialist MSP Tommy Sheridan.

Gail Sheridan and Angus Healy went to Edinburgh's Gayfield police station as detectives continued their probe into allegations linked to his defamation trial.

Mr Sheridan, who left the Scottish Socialists to set up his own party, Solidarity, was charged with perjury in December, around 16 months after his defamation trial against the News of the World.

Mrs Sheridan and Mr Healy, who were key witnesses during the 23-day trial at the Court of Session in Edinburgh, arrived at the city centre police station shortly after 1pm.

They drew up in a silver Honda car driven by Mr Sheridan, having left their home in the Cardonald area of Glasgow at around 11.30am.

Mrs Sheridan, dressed in a black coat, black knee-high boots and dark sunglasses, was surrounded by a large crowd of reporters, photographers and camera crews as she went into the station.

She made no comment to waiting reporters, but Mr Sheridan said they would be making a statement later.

Mrs Sheridan, who stood by her man throughout the trial, reportedly received a letter from Lothian and Borders officers telling her to present herself at a police station this month.

Today, Mr Sheridan said a statement would be made later in the day.

Mr Sheridan was awarded £200,000 in damages after he won his case against the Sunday newspaper.

The jury of six men and five women dismissed lurid allegations made by the paper about the former MSP's private life.

Mrs Sheridan, a star witness in her husband's defence, told the court he "would be in the Clyde with a piece of concrete tied round him" if she thought he had attended swingers' clubs.

And Mr Healy provided an alibi for Mr Sheridan for two instances when witnesses alleged he had taken part in a threesome in a Glasgow hotel suite.

Judge Lord Turnbull said that conflicting evidence may have meant some people had been perjuring themselves - an offence which could lead to a prison sentence.

The trial, in which several members of the Scottish Socialist Party gave evidence against Mr Sheridan, resulted in a split, with the firebrand politician later establishing his rival party.

Prosecution authorities later instructed the police to investigate allegations of perjury by witnesses during the trial.

The paper is appealing against the verdict and Mr Sheridan has not yet received the money. The appeal was put on hold in September last year until a Crown inquiry could be completed.

Mr Sheridan, 43, was detained and subsequently charged with perjury two months ago when police officers swooped outside an Edinburgh radio station, minutes after he had finished his weekend show.

He insisted he was the victim of a "political witch hunt" and said the fight to clear his name would go on for as long as it takes.

Earlier this month, three colleagues who backed Mr Sheridan in the court action were also charged with perjury - former Scottish Socialist MSP Rosemary Byrne, Solidarity national secretary Graeme McIver and member Jock Penman.