Three police officers showed a complete lack of “sufficient and properly rigorous investigation” while probing the tragic death of a three-year-old boy, a misconduct panel was told.

Riley Siswick died after his morther's boyfriend Kyle Campbell, battered him so badly that his bowel severed.

The boy had been left to die soaked in his own urine and was discovered in his bedroom two days later on February 6, 2016, after suffering fatal infections.

The panel heard “serious concerns” had been raised about the family to the police.

Three officers involved in the initial investigation are alleged to have breached professional standards in the way they handled Riley's death.

A second investigation by West Yorkshire detectives found that Riley had been killed by Campbell, who was later convicted of murder, and jailed for life with a minimum term of 20 years.

Leeds Crown Court heard that Campbell, the then partner of Riley's mother Kayleigh Siswick, had inflicted a blow “either from a fist or by jumping or stamping”.

Siswick was jailed for seven years after being found guilty of causing or allowing the death of a child.

Officers Det Chief Insp Mark Swift, Det Insp George Bardell and PC Oliver Scoones, all deny misconduct and gross misconduct.

The three officers claim they had a lack of experience or training in dealing with unexplained child deaths when they gave evidence, a misconduct hearing at Wakefield heard.

Ian Skelt, acting on behalf of the appropriate authority, today said that nobody was questioning the officers honesty and integrity but they did a “bad job” during the investigation.

He told a panel, sitting at the West Yorkshire Police headquarters in Wakefield, the three officers were working on the basis that Riley's death had “an innocent explanation”.

In a post-mortem examination, held on February 8, 2016, in the presence of PC Scoones and DI Bardell, it was said the boy's bowel had been separated and that this was the probable cause of death.

The hearing was told that in a log written the next day, DI Bardell stated that the injury seemed to be “50/50 between being a medical defect and a trauma”.

No approach was “materially” changed even after a forensic pathologist provided a final report on May 19, 2016 ruling out a medical cause of death and telling officers that the injury was caused by traumatic force.

Mr Skelt said: “The possibility of this being a death that related or was caused by non-accidental trauma was clear.

“From the outset, there was too much of a closed attitude to investigating this case.

Officers appeared to work on the basis that this was something that had an innocent explanation.

“There was an absence of sufficient and properly rigorous investigation.”

In the days before Riley's death there were concerns raised by his nursery that the relationship between the tot and his mum's partner was “not good”, a misconduct panel were told.

Mr Skelt said information from the local authority provided to the police about Riley's family life after his death should have been a “red flag” to officers.

“Information from the school suggested that Riley's relationship with the partner was not good, “ Mr Skelt said.

“There were reports on several occasions where Riley was highly distressed. All of this is building quite a worrying picture.

“There was information being flagged to police from various sources that needed to be investigated.”

Following Riley's death, Mr Skelt told the hearing that the officers failed to keep a policy log which would have documented clearly decisions and actions taken.

A misconduct panel heard that Riley's body was released for burial at a time when there was a potential for suspects on March 1, 2016, according to Mr Skelt.

“There was no time to release the body for a funeral, added Mr Skelt. “There were potential suspects.

“There was an ongoing investigation, the death needed to be properly investigated before the body was released.”

Mr Skelt also told the hearing that mobile phones were not seized until early March 2016.

“While it's impossible to know whether that had any practical result, it was a basic investigative step to take early on in the process,” he added.

“The longer that you leave it, the greater chance there is of something being lost.”

Mr Skelt told that hearing that even when a pathologist expressed a clear opinion that Riley's death was a result of trauma, “the approach of the officers did not really materially change”.

He said: “The officers remained of the view that this report did not change anything.”

Giving evidence at the hearing, Home Office patholigist Kirsten Hope said that at the post-mortem examination two days after Riley's death she discussed with Mr Bardell and PC Scoones and another doctor how there were three possible causes of Riley's separate bowel.

She said these were a medical cause, accidental trauma and non-accidental trauma.

At effectively the end of the initial investigation, no arrests had been made and nobody had been spoken to under caution before a final report filed to DCI Swift on June 22, 2016, a misconduct panel heard.

A hearing yesterday (Mon) heard that paramedics attended Riley's home on the day the boy was found dead and his mother appeared “hysterical”.

Mr Skelt said that after the child had been declared dead, a consultant paediatrician identified 14 separate bruises including a horizontal row across his back.

However, at the time it was felt that none of the marks helped identity a cause of death, he said, and no photographs were taken of the bruises even though photographic evidence should have been.

In a post-mortem examination held on February 8, 2016 in the presence of PC Scoones and DI Bardell, it was said the boy's bowel had been separated and that this was the probable cause of death.

The hearing was told that in a log written the next day, DI Bardell stated that the injury seemed to be “50/50 between being a medical defect and a trauma”.

The case, which is expected to last two weeks, continues.