The United States has botched the handling of inmates at Guantanamo, holding men for years without reliable evidence while releasing others who posed a grave threat, according to leaked secret files.

The trove of more than 700 classified documents released by the anti-secrecy website WikiLeaks showed US officials struggling with often flawed evidence and confused about the guilt or innocence of detainees held at the prison at the US naval base in Guantanamo Bay, Cuba.