The 2-month-old baby is pronounced dead in the St John's Hospital on Cheung Chau island. Photo: Wiki Commons

A 31-year-old mother pleaded not guilty to manslaughter in a Hong Kong court on Tuesday after she was accused of killing her two-month-old son on the outlying island of Cheung Chau in 2015.

The new mother, Leung Siu-fong, found her son Matthew Lee Man-hin suffering from convulsions, his face had turned pale and finally stopped breathing on the afternoon of August 25, 2015, the Court of First Instance heard on Tuesday.

Leung called the police, but the baby was pronounced dead upon arrival at St John’s Hospital on the island.

The first-time mother told the police that she found her son’s crying too loud after waking up from a nap. She admitted that she had grabbed the baby’s neck, shook him and threw him onto the bed.

She had also slapped the newborn and pinched his cheeks, Sing Tao Daily reported, quoting the prosecutor.

A government pathologist found that the baby had died from abusive head trauma, or known as shaken baby syndrome, and suffered from bleeding between his skull and brain, Apple Daily reported.

Injuries on the baby’s body were made one to two weeks before boy’s death, the autopsy report said.

The case continues today.