In a campaign spearheaded by Ms Bhutto, Asif Ali Zardari took action after the British government agreed to help the present Pakistani government's current investigations.
Mr Zardari is in custody in his homeland.
Yesterday, a judge at the High Court in London gave him leave to seek a declaration that he is entitled to access to the letter of request from Pakistan that triggered the investigation - which he says is politically motivated - or at least to know the substance of its contents.
But Mr Justice Latham refused to allow Mr Zardari's lawyers to apply for a ruling that the Home Secretary, Jack Straw, acted unfairly or irrationally in agreeing to the formal request and in nominating a court to receive evidence.
Lord Lester of Herne Hill QC, appearing for Mr Zardari, told the judge: "In this case there is a serious risk of injustice unless sufficient information is provided to enable Mr Zardari to enjoy effective safeguards in the English proceedings. This should not depend on the Pakistan government's wishes but on basic principles of fairness."
Mr Zardari, a Pakistani senator, was taken into custody shortly after Ms Bhutto was removed from office by the president in November 1996.
He was charged in connection with the murder of Ms Bhutto's brother Murtaza, as well as alleged offences of corruption and evasion of customs duty.
His lawyers argued that the Home Secretary's decision to grant assistance was not based on those charges but on the Pakistani government's confirmation that he faced drug-related proceedings in his homeland.
Ms Bhutto and her husband believed the request was part of a wider politically motivated campaign being waged by the present Muslim League government against the Bhutto family and the Pakistan People's Party, whose leader was Ms Bhutto.
Lord Lester said Mr Zardari wanted access to the letter of request to enable his lawyers "to have a fair opportunity to cross-examine witnesses" supplying information to nominated magistrates at Bow Street court for eventual transmission back to Pakistan.
The judge agreed that there was "an arguable case". Mr Zardari's London- based lawyers, Goodman and Derrick, then indicated that they would ask the magistrates to continue an existing order and keep police investigations on hold pending Mr Zardari's full judicial review application, due on 11 March.Reuse content