Health officials in the U.K. face scrutiny after it came to light that state run hospitals have been incinerating fetuses along with their garbage. According to an investigation by the U.K.’s Channel 4 news program, the bodies of some 15,500 aborted and miscarried babies were burned as “clinical waste,” some of which has gone to heating the facilities.

The investigation found that 27 National Health Service (NHS) trusts had incinerated fetal remains in the last two years. Ten NHS trusts admitted to the practice, two of which said the aborted and miscarried fetuses were disposed of in the hospitals’ “waste-to-energy” system, which generates heating for the facilities.  

Health officials condemned the incinerating of fetuses on Sunday and immediately called for a moratorium on the practice.

“This practice is totally unacceptable,” U.K. Health Minister Dan Poulter said in a statement, according to The Telegraph. “While the vast majority of hospitals are acting in the appropriate way, that must be the case for all hospitals and the Human Tissue Authority has now been asked to ensure that it acts on this issue without delay.”

According to The Telegraph, Ipswich Hospital NHS Trust, located in Suffolk, incinerated 1,101 fetuses between 2011 and 2013. Addenbrooke’s in Cambridge, one of the U.K.’s leading hospitals, incinerated 797 aborted or miscarried fetuses under 13 weeks gestation at its on-site “waste-to-energy” facility. Many of the mothers were reportedly told the bodies had been “cremated.”

NHS medical director Bruce Keogh said hospitals should cremate or bury the bodies of aborted babies rather than incinerating them. The BBC reports that Poulter has asked Keogh to implore hospitals to stop incinerating fetal remains.

“I have asked Professor Sir Bruce Keogh … to write to all NHS hospital trusts, to make it clear that it must stop now,” Poulter said. “The chief medical officer has also written to the Human Tissue Authority to ask them to make sure that there is clear guidance on this issue.”

The Human Tissue Authority (HTA) provides guidelines to hospitals for the disposal of human remains, including fetuses. Hospitals are supposed to inform women who have an abortion or miscarriage of the options that are available for handling the remains. While incineration is not illegal in the U.K., the practice is considered inappropriate. The HTA recommends that fetuses be cremated or buried.  

"I am disappointed trusts may not be informing or consulting women and their families,” Mike Richards, chief inspector of hospitals, from the Care Quality Commission, said in a statement, according to The BBC. “This breaches our standard on respecting and involving people who use services and I'm keen for Dispatches to share their evidence with us.”

The Channel 4 program on the investigation airs Monday night.