GENEVA (Reuters) - A United Nations human rights watchdog has called on Bahrain to release three relatives of a prominent exiled activist, describing their detention as an unlawful act of reprisal over their family connection.

There was no immediate reply from authorities in Bahrain contacted by Reuters.

It was the second time in less than a week that the United Nations has censured the kingdom after calling last Friday for the release of another activist and denouncing “continued suppression of government critics”.

The U.N. Working Group on Arbitrary Detention said three people were being held because of their kinship to Sayed Ahmed Alwadaei, a human rights activist and government critic who now lives in Britain.

His brother-in-law Sayed Nazar Alwadaei, cousin Mahmood Marzooq Mansoor and mother-in-law Hajar Mansoor Hassan were “deprived of their liberty, interrogated and prosecuted for their family ties with Sayed Ahmed Alwadaei and that these were acts of reprisals”.

The panel, composed of five independent experts, also found that there were grave “violations of their right to a fair trial and due process”. It voiced concern at allegations of torture and mistreatment in custody.

“The Working Group considers that, taking into account all the circumstances of the case, the appropriate remedy would be to release Sayed Nazar Alwadaei, Mr. Mansoor and Ms. Hassan immediately and accord them an enforceable right to compensation and other reparations, in accordance with international law,” it said.

Sayed Ahmed Alwadaei, in a statement, said: “It’s difficult for me to live freely when I know that others are imprisoned because of my actions. I just hope that this important decision influences the Bahraini authorities to end the torment of my family and grant their release.”

He called for “Bahrain’s powerful allies in the West” including the United States, to apply the full weight of their authority behind the U.N. decision and cease their support.

The Sunni Muslim ruling Al Khalifa family has kept a lid on dissent in the Shi’ite-majority country since a violent crackdown on pro-democracy protests in 2011.