Ugandan authorities arrested a man who was once detained at Guantanamo Bay on suspicion of playing a role in the death of a local prosecutor last month who handled terror cases, police said Wednesday.

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

U.S. officials tracked down Kiyemba and helped with the arrests, Enanga said.

"There was an operation which we carried out with our counter-terrorism team because we suspect that Jamal Kiyemba and his colleagues have been involved in some form of criminality," he said.

Enanga said there was no conclusive evidence tying Kiyemba to the killing on March 30 of Ugandan prosecutor Joan Kagezi, but detectives were questioning him about his possible role in that crime and a range of other offenses.

Kiyemba is a convert to Islam who once lived in Britain before he traveled to Pakistan where he was arrested as a terror suspect and later detained at Guantanamo Bay.

Ugandan police on Tuesday made several arrests over the killing of Kagezi, who is believed to have been targeted by Islamic extremists because of her public role as a senior prosecutor handling terror cases and international crimes.

Kagezi was shot twice by gunmen after she left her car — in which she was traveling with two of her children on the way home from work — to buy groceries in a Kampala suburb. After shooting her in the head and neck, the gunmen fled on a motorcycle during heavy vehicular traffic, according to local police.

Kagezi had been a prosecutor in the ongoing trial of 12 suspects accused of being involved in the July 2010 bombings here in which more than 70 people were killed while watching the soccer World Cup final on TV.

Those bombings were carried out by Al-Shabaab, the Somali Islamic extremist group which opposes Uganda's military involvement in Somalia.

The Associated Press contributed to this report.