A mother and her partner allegedly beat her young daughter so badly her injuries resembled those of a serious car crash and then played video games as the toddler lay slowly dying, a court heard.

Abigail Leatherland, 26, and her boyfriend Tom Curd, 31, are facing murder, manslaughter and gross negligence charges in a UK court following the alleged incident at their Liskeard home in Cornwall, south-west England.

The pair are accused of assaulting Eve Leatherland, who was almost two years old, so viciously that she was left with a fractured skull, broken ribs and a split liver, according to the Independent .

Toddler Eve Leatherland was allegedly beaten so viciously by her mother, Abigail, and her partner Tom Curd that her injuries resembled those of someone who had been in a serious car crash. (Facebook)

They then allegedly gave the toddler codeine – an opiate-based pain medicine that typically comes in the form of cough syrup – and put her in a cot, where she lay dying while the couple played video games nearby.

Prosecutor Sean Brunton told the Truro Crown Court today that by the time an ambulance was called and had arrived, rigor mortis had already begun to set into the young girl’s body.

"The pain she must have experienced can only be imagined," he told the court.

Leatherland, 26, and Curd, 31, allegedly gave the young girl codeine medicine and then played video games nearby as she lay dying. (Facebook)

"She suffered injuries described by medical experts as being the type of injuries most commonly associated with a road traffic crash.

“The inescapable reality is that one or other or both of these people assaulted that little girl so severely that she was left with life-threatening injuries.

"But rather than taking her to hospital or phoning a doctor or doing anything else to try and save her, ultimately she was given a fatal dose of codeine."

(9news)

Mr Brunton also said that Eve had allegedly been beaten on multiple occasions leading up to October 5, the day she died, and said he found it “inconceivable” the couple were unaware of her pain, according to the Independent .