The way in which police dealt with concerns about a four-year-old boy who was eventually starved to death by his mother and left to decompose in his cot is to be investigated by the police watchdog.
The Independent Police Complaints Commission (IPCC) has announced it is examining West Yorkshire Police's conduct in relation to the death of Hamzah Khan, whose body was found in a cot at his home in Bradford in 2011, almost two years after he died.
Mother-of-eight Amanda Hutton, 43, was jailed for 15 years last year after she was found guilty of Hamzah's manslaughter and neglecting five of her other children.
At her trial it emerged that a range of agencies, including police officers, had contact with her family but no-one spotted the danger the children were in.
The IPCC said it is now investigating West Yorkshire Police's handling of concerns raised about Hamzah's welfare.
It said allegations of neglect had been made to West Yorkshire Police and other agencies prior to the discovery of the youngster's body and it had contacted the force to ask for details of complaints to police that have been reported in the media.
The commission said it will examine what action West Yorkshire Police took after concerns about Hamzah's welfare were raised. It will also look at why the matter was not referred to the IPCC in 2011.
IPCC Commissioner Cindy Butts, who will oversee the investigation, said: "The death of Hamzah Khan was a truly shocking example of the most cruel neglect imaginable and at the heart of it lies the loss of a young life.
"Our investigation will examine what action West Yorkshire Police took and also why the contact was not referred to us in 2011."
Police had extensive contact with Hutton and her family over a number of years but mainly because she was a victim of repeated domestic violence.
Hutton's trial heard how Hamzah's father, Aftab Khan, raised concerns with officers after he was arrested for attacking Hutton but detectives told the court these were investigated and no problems were found.
A serious case review in Hamzah's case published last year concluded that Hamzah was ''invisible for almost a lifetime''.
But that review was criticised at its publication by Children's Minister Edward Timpson who expressed his ''deep concerns'', saying it has failed to fully explain ''missed opportunities to protect children in the house''.
The minister wrote to professor Nick Frost, who chairs the Bradford Safeguarding Children Board, saying: ''I have deep concerns over the Hamzah Khan serious case review.
''In particular, I am concerned that it fails to explain sufficiently clearly the actions taken, or not taken by children's social care when problems in the Khan family were brought to their attention on a number of occasions.''
Alcoholic Hutton was living in what the report described as ''breathtakingly awful'' conditions with five of her young children as well as Hamzah's mummified remains when shocked police entered her four-bedroom house in September 2011.
A jury at Bradford Crown Court found she had allowed Hamzah to starve to death in December 2009 and left his body in a cot with a teddy.
The remains were only discovered due to a rookie police community support officer's tenacious pursuit of a minor anti-social behaviour complaint because she knew something was wrong.
The family was known to all the main agencies, partly due to a long history of violence Hutton suffered at the hands of Khan
But Hutton failed to co-operate with many children's services and the SCR found that Hamzah slipped below the radar and was invisible.
Detective chief superintendent Andy Brennan, head of West Yorkshire Police Professional Standards, said: "West Yorkshire Police referred this matter to the IPCC in November last year and they have decided this will be an independent investigation which we will fully support and assist in any way we can."