The complaint was lodged by a non-governmental organisation (NGO) on May 16, saying unidentified persons were picking up street dogs from Meerpet area and 'killing' them at the nearby Kongara forest, they said.
A case was registered under the Prevention of Cruelty to Animals Act and also under relevant sections of IPC, they added.
Veterinary doctors conducted a postmortem and sent the samples to a laboratory, police said, adding reports were awaited.
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