Reports alleging that detainees have continued to be tortured in Venezuela following the seizure of President Nicolás Maduro by US forces in January are concerning, the UN's High Commissioner for Human Rights, Volker Türk, says.

Maduro has been replaced in power by one of his loyal allies, former Vice-President Delcy Rodríguez, under whose leadership an amnesty bill has been passed into law.

Türk welcomed the amnesty law but warned that structural and systemic human rights concerns have persisted in Venezuela despite Maduro's ousting.

Venezuelan officials have not yet reacted publicly to Türk's remarks but have in the past dismissed allegations of torture as politically motivated.

Türk said many Venezuelans remained in arbitrary detention despite the passing of the amnesty law last month and added that there was a child among those arbitrarily detained.

Last week, the Venezuelan parliament, which is dominated by Maduro loyalists, said that more than 7,700 people had been granted full freedom under the amnesty law. However, Venezuelan prisoners' rights group Foro Penal has so far only been able to confirm the release of fewer than 700 detainees.

Foro Penal also warns that more than 500 people remain behind bars for political reasons in Venezuela, urging greater transparency from the Venezuelan authorities.

Türk highlighted ongoing reports of torture and mistreatment of detainees, including in the Rodeo 1 and Fuerte Guaicaipuro detention centres, indicating a pattern of human rights violations that continue to be documented by independent bodies.