"My stake in Rustavi-2 was seized upon instructions from Georgian President Saakashvili in 2004. I am going to file a suit demanding the return of my stake in the TV company," Erosi Kitsmarishvili said.
He also pledged to do everything possible to make the Georgian media "free and independent" again.
Kitsmarishvili, 44, was the owner and director of Rustavi-2, a channel that analysts say did much to shape the political climate in the run-up to the 2003 Rose Revolution which brought Saakashvili to power.
Rustavi-2 went bankrupt in 2004 and a government official replaced Kitsmarishvili. The former ambassador said earlier that the television company was controlled by the Geomedia Group, registered in an offshore zone in the Marshall Islands and owned by Saakashvili. This has not been verified by independent sources, however.
Kitsmarishvili accused Tbilisi on Tuesday of failing to use all the opportunities available to it to prevent August's military conflict over breakaway South Ossetia and establish dialogue with Moscow instead. He said both countries were responsible for the five-day war.
According to Vremya Novostei, a popular Russian daily, on Wednesday the former diplomat told a Georgian parliamentary commission investigating the conflict that Tbilisi had in April considered an attack on Abkhazia, another breakaway republic. He also said that Saakashvili had planned to move the capital of Georgia to Sukhumi, the capital of Abkhazia.
The Saakashvili administration released a statement on Wednesday denying Kitsmarishvili's claims. At the same time, Pata Davitaya, head of the commission, also threatened Kitsmarishvili with criminal charges over his alleged negligence of duties.
Commenting on the threat, Kitsmarishvili said he was ready to cooperate with the Georgian prosecutor's office.
"I am ready to cooperate with prosecutors. I did not say anything new at the commission meeting. However, I was the only one from the political establishment who said openly what was going on," he said.
Tbilisi recalled Kitsmarishvili from Moscow in early July over Russian policies in the breakaway republics of Abkhazia and South Ossetia.
