Manila: A probe has begun into allegations of a proposed trade off between the release of an official arrested in the United States and the acquittal of four US servicemen being tried in a rape case in the Philippines.

The National Bureau of Investigation (NBI) summoned lawyer Harry Roque to shed light on claims that former agriculture undersecretary Jocelyn "Joc-joc" Bolante said earlier he was being used as a "pawn" to secure the release of four US Marines who were accused of raping a 22-year-old, identified only as Nicole, at the Subic Freeport in November.

Bolante made this allegation in a pleading that was submitted by his lawyer who filed a habeas corpus petition before a district court in Wisconsin in United States.

Roque, a professor at the University of the Philippines, distributed copies of Bolante's motion in Manila.

Two week ago, Nicole's mother, accused senior state prosecutor Emelie Fe De Los Santos of allegedly pressuring them to negotiate with US authorities.

Investigation

The prosecutor was quoted as saying the case would be used for a "trade off" with Bolante's case. Justice Raul Gonzalez ordered the NBI to investigate the claims on the alleged deal. Gonzalez said his department wants to know who was telling the truth.

American immigration authorities arrested Bolante on July 7 because he arrived in Los Angeles with a cancelled visit visa.

The US embassy in Manila cancelled the visa because of an arrest warrant issued by the Senate after Bolante repeatedly ignored summons for his appearance on an inquiry on the alleged misuse of a 728-million-peso (Dh48.5 million) fertiliser fund.

Critics said the fund was allegedly diverted to President Gloria Arroyo during he campaign for presidency in 2004. A group of US-based Filipino lawyers is seeking Bolante's extradition from the United States.