A 16-week-old foetus was thrown away by a hospital cleaner, it emerged yesterday. The incident happened at Bedford Hospital where dead bodies were photographed in the chapel earlier this year after it was converted into a makeshift mortuary.

A spokeswoman for Bedford Hospital said that it had apologised to the family for the error. The foetus, which should have been cremated, has not been found.

The discovery follows an investigation by hospital staff into the whereabouts of the foetus, which had been in a container awaiting cremation. It was reported as missing from the mortuary a month ago.

The hospital spokeswoman said yesterday: "A sealed container with a 16-week-old foetus inside was being taken to the mortuary to await collection by undertakers for cremation. This is in line with NHS practice where the next of kin have not expressed a wish to make their own burial arrangements.

"Unfortunately, due to an error by a member of hospital staff, the container was placed in a refuse sack in error and consequently placed in a waste compactor. Despite thorough searches the container could not be found."

Acting chief executive Stephen Bridge said: "I have thoroughly investigated the circumstances surrounding this incident and it is clear that it was due to a human error, which should not have happened. We have already apologised unreservedly to the family for any distress caused."

The controversy is the second arising from the hospital's mortuary arrangements. Last January, photographs of dead bodies in the chapel of rest ­ which was not refrigerated ­ were published in national newspapers. The eight corpses were being stored there instead of in the hospital morgue. The chief executive of the hospital, Ken Williams, resigned as a result of the outcry.

Earlier this week, Mr Williams spoke out against a new health watchdog's report on Bedford Hospital NHS Trust. He strongly criticised a report published on Tuesday by the new Commission of Health Improvement (CHI), which spoke of a "them and us" culture prevalent at Bedford. Interviewed in the Health Service Journal, he said: "I just don't accept it."

He argued that the CHI had given too much weight to anonymous opinions at the expense of solid evidence, including staff attitude surveys carried out by the Trust. The report said many staff had indicated they were afraid to "whistle-blow" when incidents occurred in case they were branded as troublemakers.