The charges include blackmail, money laundering, abuse of office, and professional negligence.
The ex-minister was detained Thursday, two days after he announced the creation of an opposition movement, For United Georgia, and criticized Saakashvili's policies.
Okruashvili's lawyers said the authorities are obstructing their efforts to provide a defense for their client, adding they have been prohibited from disclosing any information surrounding the case.
Georgian opposition parties organized earlier Friday a mass protest against Okruashvili's arrest in central Tbilisi.
Several thousand protesters called for Saakashvili's resignation, the dissolution of parliament, and early elections. Several protesters were detained when they blocked a city thoroughfare to press their demands.
Russian President Vladimir Putin said the situation in Georgia is "its internal affair" and expressed hope that all parties in the conflict will exercise restraint and show political wisdom.
A lawyer representing the ex-minister, Eka Beselia, earlier called the arrest political, and linked it to Okruashvili's comments made in an Imedi TV interview on Tuesday, in which he accused President Saakashvili of corruption and an attempt to kill businessman Badri Patarkatsishvili. He also alleged Georgian authorities had covertly planned to seize control over the breakaway republic of South Ossetia in 2006.
"The deadline was the spring of 2006. Only three or four persons were privy to it: the president, myself, Interior Minister Vano Merabishvili, and Prosecutor General Zurab Adeishvili," he told Imedi. However, he said the Georgian president lacked the resolve to order Russian peacekeepers out of the conflict zones.
