Okruashvili, an outspoken critic of President Mikheil Saakashvili, had earlier pleaded guilty to professional negligence and partially guilty to charges of extortion. The former minister has also been charged with blackmail, money laundering, and abuse of office.
"Okruashvili posted bail at around 1:00 a.m. local time [Tuesday] (9:00 p.m. GMT Monday)," the spokesman said.
According to Givi Papuashvili, the ex-minister's lawyer, Okruashvili paid the $6 mln with a mixture of cash and real estate. The lawyer added that his client would stay at his own apartment as he awaited trial.
The former minister was detained in late September, days after announcing the creation of an opposition movement, For United Georgia.
His supporters called the arrest political, and linked it to Okruashvili's comments made in an Imedi TV interview on September 25, in which he accused President Saakashvili of corruption and an attempt to kill businessman Badri Patarkatsishvili. Okruashvili also alleged that Georgian authorities had covertly planned to seize control of the breakaway republic of South Ossetia in 2006.
On Sunday, Okruashvili unexpectedly withdrew his accusations of corruption against the president. However, one of his lawyers said that her client had testified under duress, and in the absence of his legal counsel.