Sudan's deposed president Omar al-Bashir was moved to Kobar prison in the capital Khartoum late on Tuesday, two family sources said.
Bashir is being held under tight security in solitary confinement, a source at the prison said.
Since his removal by the military last Thursday, Bashir had been detained under heavy guard in the presidential residence inside the compound that also houses the Defense Ministry, the family sources told Reuters.
Another family source also confirmed to AFP that Bashir was transferred to Kobar.
Witnesses said there was a heavy deployment of soldiers and members of the paramilitary Rapid Support Force outside the prison in north Khartoum.
"There are troops in vehicles mounted with machine-guns near the prison," a witness told AFP.