Besides over 840,000 euros ($970,000) as well as various other currencies, the eight-and-a-half-hour-long raid at the ultrAslan chief's house also yielded a handgun, ammunition and four bulletproof vests, according to the DHA and IHA news agencies.
Sebahattin Sirin, who was arrested on Sunday, is accused of selling tickets on the black market, causing breaches of the peace inside sports stadiums and spreading false information.
The previous day, the ultras chief accused Turkey's justice minister Akin Gurlek on X of being part of a "group within the state that wants to make Fenerbahce champions this season" at the expense of the reigning Super Lig winners.
Neither the minister nor Fenerbahce, Galatasaray's bitter cross-town rivals, has responded publicly to that accusation.