Attorneys representing Abdel Hakim Belhaj confirmed they have served papers on Straw regarding a rendition operation mounted with the aid of British intelligence, The Guardian reported.
Belhaj and his wife allege Straw was complicit in the "torture, inhuman and degrading treatment" they received after being abducted in a so-called rendition operation involving agents from the United States, Thailand and Libya.
Belhaj's wife Fatima Bouchar told The Guardian that in March 2004 she was chained to a wall for five days in a secret prison in Bangkok before being taped from head to foot, placed on a stretcher and flown to Tripoli, Libya.
Straw already faces questioning by Scotland Yard as part of a criminal investigation into the rendition operation begun by the Crown Prosecution Service.
MI6 did not deny involvement in the operation after papers outlining its role were discovered last fall in an abandoned Libyan government office.
Reports surfaced recently that MI6 confronted Straw with evidence that he was the minister who personally authorized the operation.