* Government questions legality and fairness of U.N. inquiry
* Unclear how U.N. can conduct its planned investigation
* Colombo blames Tamil diaspora groups for allegations
By Shihar Aneez and Ranga Sirilal
COLOMBO, April 7 (Reuters) - Sri Lanka will not cooperate with a United Nations inquiry into alleged war crimes by government forces and separatist Tamil Tiger rebels in the final phase of their 26-year war, its foreign minister said on Monday.
The UN, through a United States-led resolution, last month set an international inquiry into the alleged war crimes and human rights abuses after the island nation's government had failed to investigate them properly.
Sri Lankan government has rejected the allegations.
Foreign Minister Gamini Lakshman Peiris said the government had not accepted the UN investigations due to concerns over its legality, fairness, and some conflict of interest issues.
"Where the government is required to do anything to support the investigation or to participate in it, the government will not do that," Peiris told a Foreign Correspondents Association (FCA) forum on Monday. "Nobody can come here without the cooperation of the Sri Lankan government."
However, the government will not prevent anybody from giving evidence to any such investigation as there could be various views from different people, he said.
A UN panel has found credible evidence that around 40,000 mainly ethnic minority Tamil civilians were killed in the final phase of the war due to indiscriminate shelling, mostly by the army. Sri Lankan authorities have rejected the allegation.
Citing concerns over resurgent of terrorism activities, Sri Lanka last week banned 16 Tamil organisations including the separatists Tamil Tigers. Most of the banned organisations had been pushing for an international war crimes inquiry.
It is still not clear how the UN would conduct its probe, Peiris said.
"They will have to tell us what they want to do. But the clear policy decision had been taken that we do not associate ourself with the inquiry and we do not submit to the jurisdiction of the investigating committee," he said.
Many rights organisations in the past have complained that Sri Lanka had rejected their visa requests, but the government has rejected the claims.
The U.N. resolution urged Sri Lanka to investigate all alleged attacks on journalists, human rights defenders, members of religious minority groups and other members of civil society, as well as on temples, mosques and churches.
President Mahinda Rajapaksa has said an economic boom in the post-war north could help reconciliation and many allegations by the West and international rights agencies are are spread by Tamil diaspora groups. (Reporting by Shihar Aneez; Editing by Tom Heneghan)