Ugandan authorities have arrested a Ugandan who once was detained at Guantanamo Bay on suspicion of playing a role in the killing last month of a local prosecutor who handled terror cases.

Ugandan police spokesman Fred Enanga told The Associated Press that Jamal Kiyemba was arrested with three others as they held a meeting in a Kampala suburb on Tuesday.

Enanga said the arrests were made with the help of U.S. officials who helped to track down Kiyemba.

Kiyemba is a convert to Islam who once lived in the U.K. before he traveled to Pakistan, where he was arrested as a terror suspect and was later detained at Guantanamo Bay, Enanga said, citing a profile of Kiyemba supplied by American officials.

No more details were immediately available.