The accident occurred around 5.30 am when a police vehicle hit a tree on the Washim-Amravati Road, around 200 kms from Nagpur.
"The victims belonged to the Amravati ACB (Anti-Corruption Bureau) and had come to Washim for a trap case along with our local ACB. They were bound for home after completing their duties late last night," police official Santosh More told IANS.
The deceased comprised two anti-corruption bureau inspectors and four constables, including the driver, More said.
Two constables were admitted to a hospital in Amravati while one, with minor injuries, was allowed to go home after treatment, he added.
According to preliminary investigation, the accident could be the result of driver dozing off at the wheel after working for long hours on duty.