This is according to a source at the Economic and Financial Crimes Commission (EFCC).
Mr Obiano was arrested by the EFCC on Thursday evening at the Murtala Muhammed International Airport in Lagos, hours after handing over to Governor Charles Soludo.
According to the EFCC source, he was arrested for misappropriating N5bn Sure-P and N37 billion Security Vote funds, which was withdrawn in cash.
Part of the funds were also allegedly diverted to finance political activities in the state, the source added.
Mr Obiano is said to have been moved from Lagos an EFCC facility in Abuja.
The former Governor, who has been on the Commission’s watchlist for months, was arrested at about 8.30pm on Thursday.
He was reportedly on his way out of the country to Houston, Texas in the United States.