MEMPHIS, Tenn. (AP) — Records show at least three dogs were starved to death at the city-operated Memphis Animal Shelter.

The Commercial Appeal reported details of a search warrant executed last week were made public Tuesday.

The raid by Shelby County Sheriff's officers came after a whistleblower complained animals were being mistreated.

Citing records, the newspaper reported a female mixed breed puppy that was brought to the shelter in August died within three weeks of what was described as "non-accidental starvation." A veterinarian said the dog had lost one-quarter of her body weight.

District Attorney Bill Gibbons said criminal charges are possible in the case.

City animal services administrator Ernest Alexander and 10 shelter employees were relieved of duty, but Memphis Mayor A C Wharton said Tuesday that the employees are back on the job as he awaits an internal investigation about shelter operations.

"I can't say at this point whether they did everything right or did everything wrong until I get the results, which I will have at the end of the week," said Wharton

Wharton said that volunteers are providing an "additional layer of oversight" over the employees.

Deputies seized 17 boxes of documents, four computers, six CDs or DVDs, empty dog food bags and two cell phones, according to the warrant.

Among the potential charges are aggravated cruelty to animals, official misconduct and tampering with or fabricating evidence, which could result from dogs being held for court that were allowed to die, according to the Sheriff's Office.

Photos of the emaciated dog were taken by the tipster, who repeatedly brought the dog's condition to the attention of shelter employees, said Sheriff's Office spokesman Steve Shular. A necropsy showed that the puppy hadn't eaten in at least 72 hours.

According to the warrant, volunteers at the shelter had sent numerous e-mails to the administrator, as well as Division of Public Services and Neighborhoods director Kenneth Moody, warning that animals were in poor condition.

Moody retired from the position in July.