(Adds prosecution office's reaction)
By Andrew Heavens
KHARTOUM, Jan 27 (Reuters) - The International Criminal Court prosecutor's case against Sudan's president is riddled with flaws and should be postponed, a leading Sudan expert who has been heavily critical of the government said on Tuesday.
The ICC chief prosecutor has accused President Omar Hassan al-Bashir of orchestrating genocide and crimes against humanity in the Darfur region. The court's judges are expected to decide within weeks whether to issue an arrest warrant.
Alex de Waal, a program director at the New York-based Social Science Research Council, published a paper on its website (www.ssrc.org/blogs/darfur/ ) dismissing the prosecutor's case as a mess.
De Waal, who has chronicled atrocities in Darfur, said chief prosecutor Luis Moreno-Ocampo had failed to prove his central charge that Bashir personally set out to mastermind genocide.
"If the Public Application represents the approach that the Prosecutor would take in a future trial, we face the prospect that President Bashir might well be acquitted of genocide and also quite possibly the other charges too," he wrote.
The prosecutor was using a risky and unproven strategy to prove Bashir was responsible for other war crimes and had made factual errors in the supporting paperwork, De Waal said.
"The prosecutor has presented its evidence to the judges of the ICC and the judges of the ICC will decide (on the request for an arrest warrant) in due course," a spokeswoman for the office of the court's chief prosecutor in The Hague said.
The court began its first trial on Monday, of Congolese warlord Thomas Lubanga. Defence lawyers criticised the procedure used by the prosecution and said he could not get a fair hearing.
De Waal recommended that the global court's pre-trial chamber return the arrest warrant application for Bashir to the prosecutor's office for further consideration.
De Waal also urged members of the United Nations Security Council to use their powers to postpone the case.
He said Bashir should face no charges before a 2005 deal to end a north-south civil war is implemented. Many analysts think the deal, providing for a 2011 referendum on southern secession, could be knocked off course by a warrant against Bashir.
International experts say 200,000 have died and more than 2.5 million been driven from their homes in Darfur since mostly non-Arab rebels took up arms against the government in 2003. Khartoum puts the death count at 10,000.
Fighting in Darfur has escalated ahead of the expected ruling by the judges on whether to issue a warrant for Bashir.
Sudan bombed rebels close to the regional centre of El Fasher on Tuesday and clashed with insurgents around the southern town of Muhajiriya, the region's joint U.N./African Union UNAMID peacekeeping mission said.
Sudan's government has accused Darfur's rebel Justice and Equality Movement of building up troops in Darfur to launch a major attack on the eve of the ruling by the ICC judges. (Additional reporting by Aaron Gray-Block in The Hague; editing by Matthew Tostevin) (For full Reuters Africa coverage and to have your say on the top issues, visit: af.reuters.com/ )