According to senior officials in Islamabad, the Pakistani authorities are trying to block accounts they claim were held by the Bhuttos in no less than nine countries, including Britain and France, and totalling between $50m (pounds 31m) and $80m in Switzerland alone.
In Berne, the Swiss Federal Office of Police Affairs described the measure as "provisional and preventative," taken at the request of another government. But in Islamabad an exultant Seifur Rehman, a senior official in charge of the corruption probe, hailed the Swiss action as "a milestone" in efforts to build a watertight case against the Bhuttos.
Mr Rehman said the accounts, believed to be held in four Geneva banks including the local subsidiary of Barclays, Barclays Bank (Suisse) SA, belonged to Ms Bhutto, her husband Asif Ali Zardari, her mother Begum Nusrat Bhutto, and her father-in-law Hakim Ali Zardari. "The royal couple made billions overnight by underhand deals," Mr Rehman angrily charged at a press conference. At the same time he produced bank statements and other documents purporting to show that the accounts contained kickbacks paid for commercial concessions handed out by the family before Ms Bhutto was sacked as prime minister in November 1996.
"They tailored rules and regulations and altered policies and procedures," he went on, accusing the family of setting up a web of offshore companies to channel money into the foreign accounts. But Ms Bhutto's Pakistan People's Party (PPP) branded the allegations "a sheer lie," and part of a "blitz of character assassination" against her and Mr Zardari.
Swiss spokesman said the request had come in a fax on 8 September from Islamabad, and that relevant accounts and safe deposit boxes had been blocked the same day. In London a Foreign Office spokesman refused to say whether the British government had received a similar request.
The anti-corruption probe against the Bhuttos was intensified when her longstanding political foe Nawaz Sharif became prime minister in February. Three months earlier Ms Bhutto was sacked amid charges of corruption and misrule and her husband was thrown into jail, charged with involvement in the death of her brother Murtaza, who had broken with Benazir, and was killed in a shootout with police in September 1996 .
The next step will be submission of the evidence against the Bhuttos to Pakistan's government watchdog commissioner and to the courts, who will decide on any arrests. Mr Rehman said, he would give the commissioner a further 30 police reports linking Ms Bhutto and her husband to corruption cases during her time in power between 1994 and 1996.
In Berne, officials gave no word on how much the suspect accounts contained. But they have told Pakistan it must make a formal request for legal assistance and provide more documentary support for the accusations within three months. At that point the Swiss authorities will decide whether to take the matter further.
The pursuit of Ms Bhutto as well as her husband dims hopes of a political comeback by Benazir, after the PPP's disastrous showing in the last election in which it won just 17 of 217 seats in parliament. According to associates she had recently made up her mind to abandon her husband - not only because of mounting evidence he had been behind her brother's murder, but because association with a man reviled as "Mr 30 per cent" was a deadly drag on her political ambitions.
Apart from Barclays, the other three banks named by Mr Rehman were the Union Bank of Switzerland, Citibank Switzerland and Cantrade Ormond Burrus Privee.Reuse content