World Bulletin/News Desk

Prosecutors at a United Nations war crimes court urged judges on Monday to order the return of a hardline Serb nationalist defendant freed last month on grounds of ill-health, only to throw himself back into Serbian politics.

Vojislav Seselj, 60, who suffers from cancer, was released on "humanitarian" grounds after almost 12 years in detention but still short of a verdict in his war crimes trial.

He has since rallied supporters and taken to television and radio to defend the bellicose nationalism he propagated during the bloody break-up of federal Yugoslavia in the 1990s.

Seselj's performance has further embarrassed the U.N. war crimes tribunal in The Hague - which had already drawn fire for keeping Seselj in lengthy detention without an end to his trial - and triggered a spat between former foes Serbia and Croatia.

In a published motion for his release to be revoked, prosecutors noted that Seselj had said he would never return voluntarily to the court and they said he had threatened people cooperating with the prosecution.

"He has clearly demonstrated that his health condition is no barrier to making unacceptable public statements that are inflammatory and insulting to victim communities," the prosecutors' motion to the court said.

"He has also made public statements that call into question the Trial Chamber's assessment of the extremity of his health condition."

The motion called for the release to be revoked and for an urgent court hearing to consider Seselj's health condition and under what conditions he might be allowed out again. Serbian doctors say Seselj has cancer of the colon which has spread to his liver.

It was not clear when the court might rule on the request.

If it orders his return, and Seselj refuses, the Serbian government would be obliged to arrest and extradite him.

The government is led by Aleksandar Vucic, a former close aide to Seselj but who renounced the ultra-nationalism of his old mentor in 2008 and swung behind Serbia's bid to join the European Union.

Seselj's Radical Party, in a statement, said he would not heed any call to return to The Hague.

Seselj stands accused of inciting followers to commit murder, ethnic cleansing and other war crimes in Croatia and Bosnia.

Croatian Prime Minister Zoran Milanovic last week cancelled a planned trip to Serbia this month, saying Belgrade had failed to distance itself from Seselj's remarks since his return. Vucic said Seselj had nothing to do with the Serbian state.