GENEVA, Sept 28 (Reuters) - Israel's raid on an aid flotilla bound for Gaza could end up as a case before the International Criminal Court (ICC), a lawyer who investigated the May raid for the United Nations Human Rights Council said on Tuesday.

The mission investigating the raid was not asked to make any recommendations and did not do so. But the suggestion that the case could end up at the ICC -- to which Israel is not a signatory -- maintains pressure on Israel over the incident.

Pakistan, on behalf of the Organisation of the Islamic Conference (OIC), proposed a resolution on Monday at the council calling on the U.N. General Assembly to consider the report of the three-member fact-finding mission.

The council will vote on the resolution on Friday and it is likely to pass because the OIC and its allies have a majority in the 47-member body.

The mission, with which Israel refused to cooperate, found that the commando raid, in which nine pro-Palestinian activists -- eight Turks and a Turkish-American -- were killed was unlawful and violated human rights and international law.

Israel, which has blockaded Hamas-ruled Gaza since 2007, dismissed the U.N. investigators' work in advance as unnecessary and irrelevant, and has said the human rights council is hopelessly biased against the Jewish state anyway.

The Mavi Marmara, the ship on which the nine were killed, was flying the flag of the Comoros Islands, which is a party to the Rome Statute setting up the ICC, said Sir Desmond de Silva, a prominent British lawyer on the mission.


DENIAL OF BIAS

As a result the case could theoretically end up before the ICC, he said. It is in the hands of others to take forward or not as the case may be, de Silva told a news conference.

Like other members of the mission, de Silva rejected U.S. and Israeli statements that its work had been biased.

We've done, I think, an honest job in a reasonable time and so far as my conscience is concerned we've arrived at decisions that were spot on, he said.

We went where the evidence led us.

The chairman of the mission, Trinidadian judge Karl Hudson-Phillips, said that under the principle of complementarity, a country had the right to conduct its own investigation into serious allegations before they went to the ICC, provided it was a genuine investigation and not a sham.

Whether or not the principle of complementarity can be said to apply to the steps that the government of Israel has taken is doubtful in my view, he said.

Hudson-Phillips said he was unaware of any criticism of fact in his report made by Israeli authorities except for differences between the mission's assessment and an Israeli investigation of accounts of the treatment of three Israeli commandos who boarded the Mavi Marmara and were briefly taken prisoner.

He said the Israeli authorities had confiscated photographic evidence taken by journalists and other passengers on the ship in what appeared to be an attempt to control information.

Israeli officials, Hudson-Phillips said, had also banned military personnel who took part in the operation from giving evidence to the Jewish state's own inquiry. (For mission report go to http://link.reuters.com/dem94p ) (Reporting by Jonathan Lynn; Editing by Mark Heinrich)