20 September 2012 Last updated at 10:51 ET

Lia Green death: 'Significant violence' not a tragic accident

Lia Green's death was caused by "significant violence"

The investigation into the death of a three-year-old girl in Preston is being hampered by the belief it was a playground accident, said police.

Lia Green was pronounced dead at Royal Preston Hospital after her parents called the emergency services to say she was unwell on 30 August.

Police said her death was caused by "significant violence".

A man aged 22 and a woman aged 20 arrested in connection with her death have been released on bail.

'Severe internal injuries'

Det Supt Dermot Horrigan said a fall from a swing in a playground the day before Lia died was not the cause of her death.

A post-mortem examination revealed she suffered "severe internal injuries caused by violence" that caused serious injuries to her internal organs.

Officers are trying to find out where Lia was and who she was with on the 28 August until her death at 08:20 BST on 30 August.

Her family members are a "key part" of that investigation, he said.

Mr Horrigan added: "What is really important to get across is that any fall which may have incurred from a swing did not...result in her death.

"Her death has resulted because somebody inflicted significant violence on her."

A team of 30 officers are working on the investigation to establish exactly what caused her death and who is responsible for the injuries.

Lancashire Police are appealing for anyone with information or who saw Lia in the days leading up to her death to contact them.