The devastated father of a four-year-old Gold Coast boy recalled how his son told him "I love you, I miss you" the night before he was allegedly killed by his mother and stepfather.

Tyrell Cobb's father Jason Cobb told a committal hearing at Brisbane Magistrates Court he used to phone his little boy every evening to say goodnight to him.

Recalling the last time they spoke, Jason Cobb said: "I said 'how's your day, Son?' And he started telling me things he had done, I don't remember what they were. "He said 'I love you dad, I miss you'."

Cobb said Tyrell had "sounded normal" and did not appear to have been vomiting or having trouble breathing.


He said during a previous visit Tyrell told him his stepfather Matthew Scown had "slapped him on the head".

Tyrell's mother, Heidi Strbak, 33, and her ex-partner Scown, 33, are charged with his murder.

The little boy suffered massive abdominal trauma and internal bleeding but doctors say he could have been saved if he had been taken to hospital even hours before his death in May 2009.

He was found unconscious at a Biggera Waters home with 70 injuries on his body and was later pronounced dead in hospital.

Paediatric surgeon Professor Roy Kimble told the court Tyrell could have made a full recovery if he had been taken to hospital sooner and would have been in severe pain before he died.

"He certainly had a lot of bruises around his body, much more than would be expected in normal childhood play," Prof Kimble said.

Heidi Strbak, mother of Tyrell, has been charged with the 4-year-old's murder. Photo / Jodie Richter
Heidi Strbak, mother of Tyrell, has been charged with the 4-year-old's murder. Photo / Jodie Richter

Jason Cobb told the hearing of the last time he spoke to his son. Picture: Jodie Richter

"Obviously this child has had more than one blow to the abdomen. This child has had many blows to cause all the bruises on the body."

Tyrell was taken to hospital the week before his death with an injured arm and was kept in for five days after medics found he also had an infected wound on his finger.

Strbak and Scown claimed his many injuries, including bruises on his head and ears, had been caused by falls or accidents.

The court also heard evidence that Strbak colluded with her brother Bradley Allan about their witness statements during a Crime and Corruption Commission investigation last year.

On the evening her son died she allegedly went to Allan's house to try to get cannabis.

Transcripts of phone calls and text messages were read to the court of the pair discussing "strategy" and what she should tell investigators about her marijuana use.

Allan told Strbak during one conversation "you've lied half your life, you know how to lie".

He told the court on Thursday that it was a "joke" and he couldn't recall all the phone calls.

The hearing will continue on Friday when a decision is expected to be made about whether the pair will be committed to trial.