Bulekbaev was detained as he was filming outside a bank at the center of a growing scandal.
"I think Bulekbaev's temporary arrest is illegal," Atameken party leader and lawmaker Omurbek Tekebaev told RFE/RL's Kyrgyz Service. "Because Bulekbaev was there as a human-rights activist and politician, he tried to help influence the situation. I maintain that this is an illegal, crude use of force by authorities. I think this is surely political persecution." Tekebaev is a former speaker of the Kyrgyz parliament.
Bulekbaev was arrested on August 10, as he filmed at the building of Issyk-Kul Invest Bank.
That bank is at the center of a controversy over its leadership. Bank board Chairman Bolot Baikojoev, who also heads the opposition People's Will party, has accused the government of trying to oust him.
Baikojoev told reporters today that the bank was raided overnight on August 10.
He has declined to provide details ahead of a press conference scheduled for August 13.