The man leading Palestine's investigation into the death of Yasser Arafat have said that Israel is the one and only suspect in the case.

Swiss scientists said on Thursday that he was probably poisoned, after finding high levels of polonium among his remains.

Tawfik Tirawi (below) said Israel had the means and motive to carry out the killing.

He described Israel as the "first, fundamental and only suspect in the assassination of Yasser Arafat."

Mr Tirawi had asked Russian scientists to carry out their own investigation of Mr Arafat's death.

They didn't find sufficient evidence that polonium was the cause of death, but the Palestinian investigator said both teams had determined that the longtime Palestine Liberation Organisation leader had died because of "poisonous material."

"It is not important that I say here that he was killed by polonium," he said.

"But I say, with all the details available about Yasser Arafat's death, that he was killed and that Israel killed him."

Israel has repeatedly denied that it killed Mr Arafat.

"The Palestinians should stop this nonsense and stop raising these baseless accusations without any shadow of proof," said Israeli Foreign Ministry spokesman Yigal Palmor yesterday.

Israel claimed it had politically isolated Mr Arafat and so didn't need to kill him.

But the Swiss scientists said his death was consistent with polonium poisoning.

He died in a French military hospital a month after falling ill in the West Bank compound Israel had him holed up in.