Hilary Swank has said she "deeply regrets" attending a Chechen concert.
The Hollywood star said that she was unaware of abductions, extrajudicial killings and other grave abuses Chechnya's leader Ramzan Kadyrov orchestrated in the region, according to respected human rights groups and survivors.
On the Kremlin-backed Chechen leader's 35th birthday, his government organised a lavish concert in Chechnya's provincial capital, Grozny.
Several Western celebrities showed up, including two-time Oscar winner Hilary, Belgian actor Jean Claude Van Damme and British violinist Vanessa Mae.
The leader is known for spending millions on race horses and stars for his soccer team, while the southern Russian republic he heads remains plagued by poverty and unemployment.