Chuan received a letter from Clinton today asking for Thai cooperation in catching the wanted war criminal, as secretary of state Madeleine Albright telephoned Leekpai to reinforce the `call and check' reports of his death.

``Albright asked the Prime Minister whether the news reports on the death of Pol Pot were true,'' government spokesman Akapol Sorasuchart said, adding she backed Clinton's request for help should the reports be wrong. "Leekpai said he has questioned all parties concerned especially the Thai military, but so far nobody has seen the coffin," he added.

The premier, however, categorically ruled out charges that Pol Pot has been on Thai soil, saying he would be arrested immediately and prosecuted for illegal entry.

The US call came amid a revived effort by Washington to seethat Pol Pot was arrested and brought to justice for crimes against humanity following his four-year reign of terror in Cambodia in the 1970s.

Clinton's letter reached the Thai premier as the Thai military, government and the Khmer Rouge said the reviled former dictator had died of a heart attack late yesterday and that the international community had been too late to ensure a trial.

Meanwhile, former US secretary of state, Henry Kissinger is of the opinion that the Khmer Rouge might have killed its own former leader Pol Pot to avoid handing him over for trial.

Kissinger, secretary of state under presidents Richard Nixon and Gerald Ford, spoke to BBC radio after news from Thai military officials at the border with Cambodia that Pol Pot was dead. Cambodian government officials have said they want to see his body to verify his death. Kissinger said there might have been some in the Khmer Rouge who feared pressures for Pol Pot to be extradited for trial abroad. "I think so ill of the Khmer Rouge that Idon't even exclude that they killed him in order to avoid pressure of this kind," Kissinger told the BBC.

Meanwhile, human rights group Amnesty International said today the death of Pol Pot would not heal the wounds the Khmer Rouge inflicted on Cambodia during their brutal reign of terror.

``Pol Pot's legacy is a continuing cancer at the heart of Cambodia,'' Amnesty said in a statement received here. ``The failure to bring Pol Pot and his fellow Khmer Rouge commanders to justice is reflected in ongoing human rights violations in Cambodia today.''