Okruashvili was detained in Berlin on Tuesday after Georgian authorities issued a request for his arrest via Interpol, said Michael Grunwald, a spokesman for prosecutors in the German capital.
Grunwald said prosecutors would now have to decide whether to request that he be held in custody pending extradition, and that Georgia has 40 days to deliver full documentation on the case.
He did not have details of Georgia's accusations against Okruashvili, or of the former minister's response to them.
Georgia was thrown into political turmoil in September when Okruashvili, a hawkish former ally of President Mikhail Saakashvili who was dismissed as defense chief last year, accused the president of corruption and plotting to murder a prominent businessman.
He was arrested, but freed on multimillion-dollar bail after he retracted his allegations and later left for Germany.
The discovery of the submarine has unveiled a few "inconsistencies." For example, how can one explain the fact that the sub was found where it needed to be searched for from the start?
When on a state visit to Singapore, Russian President Vladimir Putin promised to revisit the discussion of the 1956 Declaration between the USSR and Japan regarding the issue of the peace treaty with Japan
The TurkStream, which runs along the bottom of the Black Sea from Russia's Anapa to Turkey, will consist of two lines, each with a capacity of 15.75 billion cubic meters of gas a year