Omisore, a former senator, was arrested on Sunday morning in Abuja, the source said.
The Osun politician’s arrest is believed to be related to allegations that he, through firms linked to him, received N1.3 billion from the former National Security Adviser, Sambo Dasuki.
Dasuki is currently being prosecuted for allegedly mismanaging about $2.1 billion meant for purchase of arms for the military.
The EFCC in March declared Mr. Omisore wanted for his alleged roles in the scandal. In response, Omisore, who was the Peoples Democratic Party candidate in the last Osun governorship election, threatened to sue the anti-graft agency for N500 million damages for defamation.