Mahyon Talib said such a death must be investigated with vigour as if a murder had taken place.

“Such deaths will cast aspersions that the police had failed to take care of the welfare of suspects  under their custody,” she said in her 32-page written judgment of a verdict she delivered recently.

Mahyon said all evidence “in whatever form” must be collected and presented to set aside such allegations.

“Unfortunately, this was not done in this inquest,” she said, adding that there was unlawful omission by police in the case of Benedict Thanilas, who died because medication was not provided.

She said police must ensure treatment and observation when suspects of high health risk were kept in lock-ups.

In her oral verdict delivered on Sept 11, Mahyon had instructed the inspector-general of police (IGP) and the attorney-general “to do what is necessary” to begin investigations and to prosecute those involved in the death of Thanilas.

She said the death of the detainee could have been avoided if he had been given appropriate medical attention.

Thanilas, 44, who was held under the Dangerous Drugs (Special Preventive Measures) Act 1985, was found unconscious in his cell at the Jinjang police lock-up on July 10, 2017.

The father of five was taken to Hospital Kuala Lumpur but was pronounced dead.

Lawyer M Visvanathan, appearing for the family, said a civil suit had been filed against 25 policemen, including the IGP, and the government, who had been named as defendants, for negligence.