By Stephanie Nebehay

GENEVA, Oct 18 (Reuters) A Swiss investigative judge said today that he had completed a long-running probe into alleged money laundering by former Pakistani Prime Minister Benazir Bhutto and her husband.

Judge Vincent Fournier, who spoke as Bhutto returned to her homeland after eight years in self-exile, said he would hand over his confidential findings next week to Geneva chief prosecutor Daniel Zappelli for action.

Zappelli has three options -- to bring the case to trial, suspend it, or dismiss it.

Fournier conceded that money-laundering allegations would be harder to prove under Swiss law after President Pervez Musharraf granted an amnesty to protect Bhutto from corruption charges at home.

''It is not impossible, but much more difficult,'' he said.

''The fact that Pakistan has withdrawn its own prosecution does not help the Swiss demonstration of money-laundering.'' At least 13 million dollars remains frozen in bank accounts in the Swiss city in connection with the criminal case, which relates to alleged kickbacks from Swiss cargo inspection companies in the 1990s, officials said.

''I regard my investigation as completed and the case is ready for the prosecutor,'' Fournier told Reuters.

To obtain a conviction under Swiss federal law, a prosecutor must prove that graft or other crimes have been committed abroad and the proceeds were laundered in Switzerland. A conviction for aggravated money-laundering can mean up to five years in prison.

Bhutto and her husband Asif Ali Zardari were convicted in Geneva in 2003 of having laundered funds worth some 13 million dollars through offshore companies and ordered to return the frozen funds to the Pakistani government, which currently remains a civil party in the case.

But this verdict was thrown out automatically upon appeal, sparking a new probe. Bhutto denied the money-laundering charges in testimony two years ago before Fournier.

Alec Reymond, Bhutto's lawyer in Geneva, said he expected Zappelli to drop the case following Musharraf's amnesty, which also applies to Zardari.

''The abandonment of the prosecution in Pakistan should lead to the affair being closed in Geneva,'' Reymond told Reuters.

Bhutto's return could eventually lead to power sharing with Musharraf, the army chief who took power in a 1999 coup.

Pakistan's Supreme Court has still to rule on the legality of the amnesty and of Musharraf's recent re-election.

REUTERS PD HT1717