Officers attached to the Stevens team investigating collusion between security forces and paramilitaries yesterday arrested a couple in connection with the murder of Mr Pat Finucane.
Scotland Yard, in a brief statement, said they had detained a man aged 40 and a woman aged 45 in Sussex. The man is understood to be Ken Barrett, though the Stevens team will not officially confirm this or that the arrested woman is his partner.
Mr Barrett, once a significant UDA figure, was brought back to Northern Ireland for questioning at around midday yesterday while the woman was questioned by police in Sussex.
They were arrested under the Terrorism Act 2000 and can be held for up to seven days before they are either charged or released. A spokeswoman told The Irish Times the pair would be questioned on the Finucane murder "and other matters", but she declined to elaborate.
Stevens team detectives, supported by Sussex police and officers from the PSNI were involved in the arrest.
Mr Barrett left his native Shankill for England following the murder in Belfast of William Stobie, a former quarter master for the UDA believed to have supplied the weapon used in the murder of Mr Finucane in February 1989. Stobie had been charged in connection with the murder.
Sir John Stevens, still conducting his third inquiry into collusion between the intelligence agencies and paramilitaries, last February said he knew who killed Mr Finucane. Britain's top police officer said this knowledge was based on intelligence reports.
Mr Barrett was secretly recorded on BBC's Panorama programme last year admitting that he was one of the two gunmen who shot the solicitor.
Mr Barrett said to reporter John Ware that an RUC officer told him: "Pat was . . . an IRA man like, he was dealing with finances and stuff for them . . . and if he was out like, they would have a lot of trouble replacing him . . . He says: 'He'll have to go. He'll have to go'. He said 'He's a thorn in everybody's side'." Mr Barrett said that, on the night of the Finucane murder, the police officer who urged him to kill the solicitor passed a message to the UDA murder gang saying that a police road-block near the scene had been taken down and that the route to the house was "all clear".
Sir John has confirmed on both his recent visits to Belfast that Mr Finucane was not a member of the IRA or any other illegal organisation. "He was a very effective and efficient solicitor," he said.
Sir John's interim report, issued last month, found that paramilitary informants and intelligence agents "were allowed to operate without effective control and to participate in terrorist crimes".