"An inquiry has been ordered and show-cause notices were issued to those in charge of the mortuary. We have to know the cause...how it happened," said Director of Medical Education (DME) Dr K Ramesh Reddy.
It is suspected that rodents had bitten the nose and some other facial parts of the body, he said.
The woman's family members, during a visit to the mortuary yesterday, found the body disfigured and complained to the hospital authorities.
"It is a modern mortuary...we have asked the officials concerned to verify how the incident happened as the body was kept in a freezer," Reddy said.
Officials have been told to take steps to ensure such incidents don't happen again, Reddy said, adding that the hospital's superintendent Dr B Nagender is also looking into the matter.
The 21-year-old woman had allegedly committed suicide on Monday by hanging herself at her house in Habibnagar here. Her body was shifted to the OGH mortuary the same night, Afzalgunj Police Station P Gnanendar Reddy said.
"No complaint (about mutilation of the body) has been lodged by her family members with the police. They have complained to the hospital officials," the Inspector said.