A toddler died just one day after a coughing fit where she started vomiting at a birthday party, it has been reported.

Isabella Lamont was 20 months old when she died after being taken to the Royal Children’s Hospital at the Victorian border town of Wodonga, Australia in October 2018.

The tot had been at a birthday party the day before her tragic death.

Later she had a fit where she turned purple, went limp and was said to be "barely breathing",according to the Coroners Court of Victoria on Tuesday.

News.com.au reports that an autopsy found she had suffered a cardiac arrest with brain swelling but how this had occurred was “unsettled”, counsel assisting Libby Murphy said.

“The cause of death was unascertained,” she added.

The Royal Children's Hospital in Melbourne
The Royal Children's Hospital in Melbourne

A doctor who performed the autopsy was reported to have found it may have been caused by head trauma, either accidental or non-accidental.

The court reportedly heard that before the birthday party Isabella was “continuously coughing” before she started to vomit through the night.

She was heard “moaning” from midnight and her dad slept with her in the living room before they got up early for the birthday lunch.

At the party other children told adults Isabella was lying on the ground in the children’s playroom.

The girl was put in a high chair and was said to have eaten some jelly with the other children but later threw it up.

She was put back into the playroom but was found lying on the ground, looking "sad" before the family left.

Patricia Lamont with her daughter
Patricia Lamont with her daughter

According to the Sydney Morning Herald it was about 5.30pm when Isabella "felt limp and was unable to hold herself up" before her body stiffened and she began to turn purple.

Medics were called and found the child barely breathing and non-responsive.

She died on October 7 at the Royal Children’s Hospital.

Her mum Patricia Lamont reportedly said the process had taken “so long” and she still wanted justice for her daughter.

She said in a statement: “I want answers. I want justice for my daughter. There needs to be accountability for those who were responsible and there need to be reforms to the systems that led to this tragedy."

Another hearing will be held later in the year in Melbourne.