A three-month-old baby died in October last year, just five weeks after she was discharged from hospital for a broken skull, a coroner's inquiry heard yesterday.

Reyhana Qailah Mohamad Shiddiq's parents Nurraishah Mahzan, 31, and Mohamed Shiddiq Sazali, 27, had signed a safety undertaking with the Ministry of Social and Family Development (MSF) before taking her home on Sept 9, 2015.

But on Oct 12, Reyhana became unresponsive while Mr Shiddiq was trying to feed her milk with one hand, while playing a game on his mobile phone. Efforts to resuscitate the infant were unsuccessful.

A forensic pathologist found that three of her ribs were broken about one to two weeks before her death.

Police investigator Tony Won told the inquiry: "Although the cause of death cannot be ascertained... smothering or suffocation is unaccompanied by visible injuries or permanent marks, but choking on milk may also be a possible cause of death." He said Reyhana's rib fractures also remain unexplained.

Yesterday, he told the court that Reyhana was born normally on June 28 last year. On Aug 9, she was taken to hospital for blood in her vomit. She was discharged after eight hours, against medical advice, as her mother wanted her home.

On Aug 26, Ms Nurraishah found Reyhana crying non-stop. At KK Women's and Children's Hospital, she learnt that Reyhana had a fractured skull. The hospital told the police and MSF of the case.

A child protection officer came up with a plan for Reyhana to be supervised by at least two adults, if she was under the family's care. Reyhana returned home from the hospital on Sept 9.

On Oct 12, Ms Nurraishah left home at about 10.20am for a drug supervision test, having fed and burped her baby. She passed Reyhana to Mr Shiddiq and told him to burp her properly. He later fed the infant, while seated with his legs crossed. But she did not want to drink and cried for about two minutes before becoming unresponsive.

He put her on the bed and patted her back. Ms Nurraishah's father, Mr Mahzan Ahmad, 57, returned home and found her not breathing, but with a pulse. He started cardiopulmonary resuscitation (CPR) with chest compressions.

Ms Nurraishah got a text message from Mr Shiddiq and took a taxi home, where she did CPR until police and paramedics arrived.

After Reyhana's death, police investigators did a lie-detector test on Ms Nurraishah, Mr Shiddiq and Mr Mahzan, Inspector Won said.

Mr Shiddiq failed the test and admitted dropping the baby on Aug 26. The inquiry will resume at a later date.