Israel has denied Lebanese accusations that it had a hand in the assassination of former Christian warlord Mr Elie Hobeika.
Lebanon has accused Israel of being behind Mr Hobeika's killing in a car bomb blast this morning.
The former Lebanese minister was co-operating with Belgian solicitors trying to indict Israeli Prime Minister Mr Ariel Sharon for war crimes.
Mr Hobeika met with the lawyers two days ago and was understood to be ready to testify against the Israeli prime minister in a Belgian court.
An internal Israeli inquiry found Mr Sharon, who was defence minister at the time of the Israeli invasion of Lebanon, was "politically responsible" for the massacre of around 1,000 people at camps in Sabra and Shatila. A Belgian court is studying whether it can accept a case brought against him by relatives of the victims.
"It is clear that Israel does not want witnesses against it in the historic trial in Belgium that will surely condemn Mr Ariel Sharon," Mr Marwan Hamadeh, Lebanon's minister of displaced people, said.
"We [in Lebanon] have already suffered from the criminal Sharon in Beirut, and Palestine today is going through the same because of him".
The charge was repeated by Palestinian leader Mr Yasser Arafat's representative in Lebanon. Sultan Abul Aynain said: "Zionist Mossad assassinated Hobeika to prevent him from testifying against Sharon at the Belgian court".
But Israeli foreign ministry spokeswoman Mr Yaffa Ben-Ari said: "Israel has nothing to do with this event. It's ridiculous".
Mr Hobeika was a Christian militia chief during the 1975-1990 civil war in Lebanon and later became a minister in the Lebanese government.
AFP