Security forces arrested Turabi and eight other party officials on January 18 after the politician called for a “popular revolution” if Khartoum did not tackle inflation.
Turabi was the spiritual mentor behind the Islamist government of Sudan’s president Omar Hassan al-Bashir when it took power in a 1989 coup, but the men later fell out.
Turabi was also reportedly close to Osama bin Laden when the al Qaeda leader lived in Sudan in the 1990s.
The leader of Sudan’s opposition Popular Congress Party gave a cautious reaction to news of bin Laden’s death in a U.S. raid in Pakistan on Monday.
“All Muslims are sad today. I don’t like the killing of any human,” he told reporters at his house in Khartoum packed with supporters and friends celebrating his release.
“Osama bin Laden had some good intentions but that does not mean I approve everything he did,” he said, describing the 9/11 attacks as a mistake.
Turabi said Sudan would not be able to cope with a full revolution like the uprisings that unseated the presidents of Tunisia and Egypt. But he said the country still needed wholesale change.
“We want a total political system change, a democracy in Sudan. A real change, not just dialogue … which we tried before,” Turabi said.
“A revolution can lead to chaos in Sudan because Sudan is dezentralised and tribalised. We need to organise a transition for change,” he said.
His comments come at a politically sensitive time for Bashir as the country’s oil-producing south is poised to split after an independence referendum in January.
Turabi has been in and out of jail since his split from Bashir’s ruling party in 1999/2000.
He said no charges had been brought forward against him.
“You enter prison without a reason and leave prison without a reeason,” he said.
Sudan’s price increases have sparked student protests in the country’s northern agricultural heartland and Khartoum.
Khartoum has long feared Turabi’s influence, believing many of his supporters still remain in key positions in the army and security services.
Turabi is usually arrested during times of difficulty for the government, most notably after Darfur rebels launched an unprecedented attack on the capital in 2008.