Parents of children whose organs were removed at Liverpool's Alder Hey hospital say they feel "let down" the doctor involved will not face charges.
Professor van Velzen stockpiled children's organs
The Crown Prosecution Service (CPS) has said there is insufficient evidence to prosecute Professor Dick van Velzen.
Parent support group Pity II condemned the decision, saying: "He stripped our children of their organs without our consent and he has just walked away."
The CPS said lawyers would meet with parents to explain their decision.
Christopher Enzor, head of the CPS Casework Directorate at York, said: "I appreciate that this will be a difficult decision for those who have lost children at Alder Hey hospital and who had to face the trauma of the issues surrounding the removal and retention of their children's organs without consent."
Paula O'Leary, founder member of Pity II - Parents Interring Their Young Twice - discovered the organs of her 11-month-old son Andrew had been kept 18 years after his death.
She said she was "absolutely gutted" charges would not be pressed.
"We all thought they would make an example of van Velzen but as far as the group is concerned he has got away with it.
"We have been fighting for more than five years for justice for our children," she said.
"Now we have been stabbed in the back again."
Merseyside Police began their investigation into the organ scandal in 2001.
An inquiry had found serious wrongdoing at the Liverpool hospital over the retention of dead children's organs.
The Redfern Report, published in January 2001, alleged many instances of serious wrongdoing at Alder Hey over a long period and recommended that the CPS investigate.
In December that year, the CPS advised Merseyside Police to investigate pathologist Professor van Velzen over the removal and retention without consent of human organs at post-mortem examination.
Mr Enzor confirmed on Wednesday that no criminal prosecution would follow.
He said police had undertaken a "very thorough investigation" during 2002 and 2003 of a "very complicated and difficult matter".
But he said the main difficulty for a prosecution, which the Redfern Report had itself identified, was that there could be no guarantee that organs which remained in containers were those originally taken at post-mortem examination.
Mr Enzor said: "This factor causes a particular problem in any prosecution as we would need to prove beyond reasonable doubt which child's organs we were talking about.
"The police have tried hard to find a solution to this problem, but they have been unable to do so."
Professor van Velzen previously told the BBC he had removed and retained the organs of 845 children at Alder Hey Children's Hospital, where he was the senior pathologist from 1988 to 1995.
He claimed this was because the hospital had not given him the resources to carry out detailed post-mortem examinations.
He was banned from carrying out any medical work in the UK in 2001, after the Redfern Report.