The administration of the National Zoological Park in Delhi purportedly covered up the deaths of at least 50 animals in 2017 to show a decrease in mortality rate, The Indian Express reported on Wednesday quoting official documents.

The report claimed that the zoo did not include the deaths of several animals, including endangered species such as the brow-antlered deer, sambar deer, black buck, white buck, spotted deer, barking deer, red jungle fowl and palm civet.

Among the several discrepancies, the zoo’s mandatory annual inventory report purportedly differed from the mortality data reported to the Central Zoo Authority. The zoo’s official records reported 91 deaths from an opening stock of 1,202 animals in 2017-’18 indicating a significant drop from the 325 deaths recorded the previous year. The annual mortality record submitted to the Central Zoo Authority lists only 75 animals.

Also, around 50 pages of the zoo’s postmortem register that records all animal deaths on its premises is missing, the daily reported. Unidentified officials claimed that the pages were reported missing soon after zoo director Renu Singh took over the post.

Central Zoo Authority chief DN Singh told The Indian Express that they were aware of “certain issues with the zoo’s postmortem records and mortality” data. “We are looking into the matter,” Singh said.

Former Central Zoo Authority chief Dr Rajesh Gopal said the offence if found true was a very serious breach of accountability. “Postmortem and reporting of death should follow scientific processes and external observers may be involved, if necessary, to ensure transparency,” Gopal said.