Fifteen people died in the attack on the Mombasa hotel in 2002
The family of a Kenyan man being held at the US prison camp at Guantanamo Bay is suing Kenya's government for $30m (£18m), their lawyer has told the BBC.
Papers filed at Nairobi's High Court say Abdul Malik was wrongfully detained and tortured after his arrest in 2007.
The Pentagon has said he admitted his involvement in the 2002 attack on an Israeli hotel in Mombasa and trying to shoot down an Israeli airliner.
But his family says he is innocent and there is no evidence against him.
The family's lawyer Mbugua Mureithi told the BBC Somali Service that Kenya's police have provided a sworn affidavit that they have no evidence against him.
The US Defense Department has declined to release a transcript of his hearing at Guantanamo, as they have done for other prisoners, the AP news agency reports.
The case is due to be heard on 14 January 2010.
In September, another Kenyan suspected of involvement in the Mombasa attacks was reportedly killed in a US military helicopter raid on Somalia.
Analysts say Saleh Ali Saleh Nabhan was one of the most senior leaders of al-Qaeda's East Africa cell.