The deposed Sudanese president Omar al-Bashir has been moved from his residence to Kobar prison in the capital Khartoum, two family sources say.
A prison source also said he was being held under tight security in solitary confinement.
Sudan's military ousted Bashir after weeks of mass protests that climaxed in a sit-in outside the Defence Ministry compound.
Protests are continuing and their leaders say the unrest will not cease until the ruling Transitional Military Council (TMC) hands power to a civilian-led authority ahead of elections.
Bashir, 75, had been detained under heavy guard in the presidential residence inside the compound that also houses the Defence Ministry, before being shunted to Kobar prison late on Tuesday, the family sources said.
Kobar, just north of central Khartoum adjacent to the Blue Nile river, housed thousands of political prisoners under Bashir's repressive rule and is Sudan's most notorious jail.
Bashir faces ICC arrest warrants over accusations of genocide and crimes against humanity in Sudan's Darfur region during an insurgency that began in 2003 and led to the death of an estimated 300,000 people.
He denies the allegations.
Australian Associated Press