Mali's ruling military junta has said it is considering charging the ousted president with high treason.
Coup leader Capt Amadou Sanogo said the junta may also charge Amadou Toumani Toure with financial misconduct.
The announcement came as the junta, which is under fire from the international community, called for a "national meeting" on Mali's future.
Army rebels deposed the government last month claiming President Toure had not done enough to fight Tuareg rebels.
"We call the entire political class and all civil society actors to... a national meeting which will begin on April 5," Capt Sanogo told journalists.
He said the meeting on Thursday would determine "what will be best for the country in a consensual, democratic fashion".
And he added that the ousted president "could be the object of judicial proceedings for high treason and financial wrongdoing", without giving more details.
'Cease military operations'
Since the military took charge, Tuareg rebels in the north have made significant territorial gains - including taking the World Heritage Site of Timbuktu over the weekend.
Mali's West African neighbours agreed on Monday to impose tough economic sanctions on the junta.
People are now hoarding fuel as a result of the sanctions, according to a BBC reporter in the capital Bamako.
Earlier, the United States expressed concern that the political crisis in Mali is allowing radical Islamists to gain ground, and threatening the country's territorial integrity.
"The United States urgently calls on all armed rebels in the north of Mali to cease military operations that compromise the Republic of Mali's territorial integrity," State Department spokeswoman Victoria Nuland said.
There have been reports of extremist Salafi groups moving into towns in the north taken over by Tuareg rebels in recent days.
On Tuesday the African Union also imposed its own targeted sanctions on the coup leaders, including travel bans and asset freezes.