The choice of a Sudanese general to head an Arab League mission in Syria has alarmed activists, who say Sudan's own defiance of a war crimes tribunal means the monitors are unlikely to recommend strong action against Syria's Bashar al-Assad.

The Arab League says Lieutenant-General Mustafa al-Dabi brings vital military and diplomatic expertise to its unprecedented mission to verify that Assad is complying with a deal to end Syria's crackdown on protesters.

But some critics of Khartoum say it is all but impossible to imagine a Sudanese general ever recommending strong outside intervention, much less an international tribunal, to respond to human rights abuses in a fellow Arab state.

Eric Reeves, a professor at Smith College in Massachusetts, who studies Sudan and has written strong criticisms of its government, said the choice of a Sudanese general was a sign the Arab League might not want its monitors to produce findings that would force it to take stronger action.

"There is a broader question of why you would pick someone to lead this investigation ... when he is part of an army that is guilty of precisely the sort of crimes that are being investigated in Syria," Reeves said.

"I think a Sudanese general would be one of the least likely people in the world to acknowledge these findings even if they are right there before him... It doesn't make any sense unless you want to shape the finding. They want it shaped in ways that will minimise the obligation to do more than they already have."

Syrian opposition activists are reluctant to publicly criticise a monitoring mission in which they have invested high hopes. But several have privately voiced concern over whether a Sudanese military man would be willing or able to take a hard stance towards Assad.

Dabi has held senior Sudanese military and government posts, including in the Darfur region, where the prosecutor of the International Criminal Court says the army carried out war crimes and the United Nations says 300,000 people may have died.

Sudan's President Omar al-Bashir has been indicted by the Hague-based ICC for genocide and crimes against humanity. Khartoum says the accusations are baseless and politically motivated, and puts the Darfur death toll at 10,000.