Three funerals had to be held for a baby girl killed by her father after police twice found they had retained body parts, it has emerged.
The family of Leah Aldridge had “no confidence” in police after learning for a second time that organs had been found, said Bolton West MP Chris Green.
Leah, from Atherton, near Manchester , died aged five weeks in 2002.
Mr Green has demanded a public inquiry. Greater Manchester Police said it would cooperate with any process.
Prime Minister Theresa May said it was an “absolutely terrible case” and expressed her sympathies to Leah’s family for their “prolonged trauma”.
Leah, who had a cold and was not sleeping, was shaken to death by her father Andrew Ashurst.
She died in hospital on Christmas Day in 2002 and Ashurst was jailed for manslaughter in 2004.
Leah’s body was initially returned to her mother, Janine Aldridge, for a funeral.
However, Mr Green said police told Ms Aldridge in January 2017 that her daughter’s liver had been found during an audit of human tissue held for police forces investigating crimes.
The audit, conducted across England, Wales and Northern Ireland, had taken place between 2010 and 2012 and police contacted some 180 families across Greater Manchester.
The remains were returned to the family and Ms Aldridge arranged another burial for Leah in March 2017, having been assured that all organs were accounted for.
“Only a few weeks ago yet more body parts were discovered by the police and the family had to go through the ordeal of a third funeral,” Mr Green said at Prime Minister’s Questions.
Mrs May said she understood the deputy mayor of Greater Manchester had been in touch with the Human Tissue Authority about the case to evaluate what went wrong.
“Officials in the Home Office will meet both the Greater Manchester Police and the National Police Chiefs’ Council to further address the issue of historically held human tissue,” Mrs May said.
“I will ensure that the relevant Home Office Minister updates my honourable friend on the outcome of those meetings.”
A spokesman from the mayor’s office said it was a “tragic and deeply distressing matter”.
He said the mayor was contacted about the case in August and has discussed it with the deputy mayor and the chief constable, and has written to Leah’s family to offer his full support.
Det Chief Supt Mary Doyle, of GMP, said: “We will of course cooperate with any inquiry as we believe it’s important the process is as open and transparent as possible.”