Sudan's ousted and imprisoned President Omar al-Bashir is being investigated for money laundering and holding large sums of foreign currency without legal grounds, a judicial source told the Reuters news agency on Saturday.
When the three-decade ruler's home was raided by military intelligence, the source said, authorities found suitcases loaded with more than $351,000 and 6m euros ($6.7m), as well as 5m Sudanese pounds ($105,000).
"The chief public prosecutor... ordered the [former] president detained and quickly questioned in preparation to put him on trial," the source told Reuters.
"The public prosecution will question the former president in Kobar prison," the source added.
Bashir, who is also being sought by the International Criminal Court (ICC) over allegations of genocide in the country's western Darfur region, was ousted on 11 April by the military following months of protests against his rule and had been held at a presidential residence.
The military council that replaced him, and who have faced continued protests demanding they hand power to civilians, said they will not hand Bashir over to the ICC.
Uganda has also said it would consider offering asylum to Bashir to protect him against the ICC, which has previously been criticised by the country's President Yoweri Museveni.
Bashir's family said this week that the former president had been moved to the high-security Kobar prison in Khartoum.
Two of his brothers were also arrested as part of a campaign against "symbols of previous regime".
The Sudanese Professionals' Association, a group leading the protests, has called for Bashir and members of his administration to be held to account, a purge of corruption and cronyism, and easing an economic crisis that worsened during Bashir's last years in power.
On Wednesday, Sudan's transitional military council ordered the central bank to review financial transfers since 1 April and to seize "suspect" funds, according to state news agency SUNA.
The council also ordered the "suspension of the transfer of ownership of any shares until further notice and for any large or suspect transfers of shares or companies to be reported" to authorities.
Sudan's new prosecutor general on Saturday lifted the immunity of security agents allegedly involved in the death of a detainee held in connection with protests, state media reported.
Ahmed al-Kheir, 36, was arrested in late January in the eastern state of Kassala by agents of the National Intelligence and Security Service on allegations that he was a protest organiser in the area, AFP reported.
His family was told to take his body from a local mortuary, and a top official in Khartoum later confirmed that Kheir had died from wounds suffered in detention.