All deaths under detention should be investigated for the cause of death, the Human Rights Commission of Malaysia (Suhakam) said following its inspection on the Juru Immigration Detention Centre in Penang.

The commission made the recommendation after its visit nearly two weeks ago, together with the Enforcement Agencies Integrity Commission (EAIC).

This followed complaints of deaths of detainees, allegedly due to abuse, allegations that the EAIC has since refuted following the snap inspection on Aug 22.

However, Suhakam noted that no post-mortem had been conducted into the death of a Cambodian national in May.

"During the visit, the commission and EAIC were informed by the Immigration officials that the allegations were unsubstantiated and that only one detainee of the Juru Immigration Detention Centre had died in 2016.

"According to the Immigration officials, the detainee, a Cambodian lady, who was being treated for heart disease at a hospital, had died from a heart attack in May 2016.

"The Immigration officials also indicated that no post-mortem was carried out on the deceased as the coroner was of the view that there was no suspicion of foul play.

"In relation to this, the commission recommends that an inquest, including a post-mortem examination, be conducted following all deaths in detention to verify the cause of the death," Suhakam said in a statement today.

Allegations of torture and deaths in Malaysian immigration custody made headlines last month after a Cambodian daily published an article detailing the ordeals of two freed Cambodian nationals who supposedly witnessed such incidents in the Juru facility.

The article sparked fresh concerns over Malaysia's already widely criticised and overcrowded immigration detention facilities and has led to calls for an urgent probe into the matter.

Despite the denial by the Immigration Department, Malaysian Trades Union Congress (MTUC) has urged a thorough and independent investigation into the allegations.