A man who was held in Guantanamo Bay is to launch legal action for damages against MI5 and MI6.
Tarek Dergoul, 29, claims the agencies knew he was being tortured while in US custody, it has been claimed.
Mr Dergoul also accuses British agents of benefiting from intelligence gathered from his alleged mistreatment and wants the court to ban them from using similar tactics in the future.
If the High Court rules in his favour, it could prevent both the security and special intelligence services from interrogating British nationals who are being held and tortured abroad.
Mr Dergoul, who is a British citizen, claims British agents repeatedly questioned him when he was held both at the Cuba camp and in Afghanistan and were therefore complicit in his treatment.
The Guardian says he will be represented in the case by Rabinder Singh QC.
A spokesman for the Foreign Office said: “The Government is aware of Mr Dergoul’s accusations.”