The deceased has been identified as 32-year-old Ramphool alias Bholu.
The body was spotted by morning walkers, police said.
The mother of the deceased cop, Krishna alias Kisna, said Ramphool was not in home till late Saturday night and his body was found in the park Sunday morning.
ASI Dilbag Singh said Ramphool used to drink and suspects it to be the reason behind his death. The body was handed over to the relatives after post-mortem, police said.