A Tampa attorney claims a lead plaintiffs lawyer in the Deepwater Horizon oil spill litigation colluded with BP in drafting a class action settlement that guaranteed more than $3 billion in legal fees.

Attorney Brian Donovan of The Donovan Law Group filed the suit Feb. 12 in HIllsborough CIrcuit Court against Steve Herman, co-lead counsel in the multidistrict litigation against BP over the 2010 spill.