P OLICE were working on their first major clue concering the escape of alleged coup plotter Sin Song as the Post went to press - with the discovery of his getaway car.

The car was found in Tak Khmao town, Kandal province, 10 km southeast of the capital on Sept 5, said Co-Minister of Interior You Hokry after a Council of Ministers meeting the following day. The direction the car was found in fuelled speculation that Song had slipped over the border into Vietnam.

"Right now we think that he[Sin Song] might be going to the East," the Minister emphasized.

But he refused to answer questions about whether Song had crossed the border, saying an investigation was still under way.

The Vietnamese Embassy could not be reached for comment as the Post went to press.

Later on Sept 6 at a press conference Information Ministry Secretary of State Khieu Kanharith said: "Maybe it is a clue, not true but a trick and maybe he went in a different way."

He added: "But I'm sure that he left [Cambodia] already. We are trying to investigate and if we find him we will bring him back."

Neighboring countries are certain to be embarrassed if Song, who is accused of being a ringleader in the July 2-3 plot to overthrow the Royal Government, emerges on their soil.

Kanharith said he was confident that Song could be brought to justice if he fled east over the border. "I think with Vietnam we can make it, because we have some arrangement," he said, adding, "But with other countries we don't have extradition treaties."

The discovery of a getaway car also backed theories that Song's escape from the Ministry of Defence safe house where he was being held under guard, was a well-planned operation.

Asked if Sin Song had any collaboration from security forces to help him get out of custody, You Hokry said: "I think that this escape could not have been made without any assistance from those people who were guarding him."

Song was Minister of National Security in the State of Cambodia regime during which he controlled the state security apparatus, including undercover police forces. He was accused of masterminding death squads which killed dozens of political opponents of the Cambodian People's Party in the run-up to last year's elections.

Reuters quoted a senior police commander as saying on Sept 6 that Song had escaped from the detention house on Sunday morning between 3 and 4 am. He was being guarded by Military Policemen.

Kanharith said following Song's escape the unit of guards watching alleged co-conspirator Sin Sen, the former Secretary of State for the Interior Ministry, had been changed. Government officials refused to elaborate on where General Sin Sen was being held.

The Secretary of State for Information admitted that Song, along with fellow alleged ring leaders and Sin Sen and and Police General Tes Choy had yet to be formally charged for their involvement in the coup plot.

"They will be charged...Not only we have to collect all the proof but we have to understand the mechanism of this coup. This will be very important for the future," said Kanharith.

Earlier the Cambodian People's Party (CPP) finally stripped Prince Norodom Chakrapong, Sin Song and Sin Sen of their party membership, following their alleged involvement in the coup attempt.

The decision was announced in a communiqué at the end of the 18th plenary meeting of the CPP's Central Committee on Aug 29-30.

The communiqué went on to say that the plenum strongly condemned the attempt to hold a coup d'état by a small group of people, which aimed at overthrowing the Royal Government.

"Their attempt to seize power totally ran counter to the principles of the CPP," it said.

Prince Chakrapong, First Premier Norodom Ranariddh's half-brother, belatedly arrived in Paris on Aug 30 after being allowed to go into exile.

French airport police said he landed at Paris' Charles de Gaulle airport from Helsinki on a scheduled Finnair flight and transferred to a domestic flight bound for the southern town of Montpellier.

A foreign ministry spokesman said Chakrapong had made no demand for asylum but had no need to do so.

"He has a valid residence permit. He can come and go freely, as he chooses," the spokesman told Reuters. A Finnair official said he was traveling alone.

Chakrapong lived for long periods in France during the 1970s and his residential permit stems from that period.

He and Sin Song lead a short-lived secessionist movement in six eastern provinces in the wake of last year's elections which is widely credited with causing winners Funcinpec to seek a coalition with their CPP rivals.- Additional reporting by Reuters