A group led by winemaker Jess Jackson paid $2.6 million for an 80 percent majority interest in rising star Curlin in 2007.

The purchase price, long held secret, has been released for the first time in a motion filed in a civil case against Curlin’s two minority owners. Until Tuesday, the sale price had been reported to be in the $3.5 million range.

Jackson headed a group with three partners in buying a majority interest in the chestnut colt from lawyers William Gallion and Shirley Cunningham Jr. Jackson later bought out his partners. Gallion and Cunningham retain a 20 percent interest in the 2007 Horse of the Year.

Gallion and Cunningham are awaiting a second trial on charges that they conspired to illegally take $65 million from clients in a $200 million settlement over the diet drug fen-phen. The motion containing the sale price was filed in a related civil lawsuit against the men.