Police shot at and injured a man believed to be the driver of the truck that mowed down a DSP in Nuh when he was probing illegal stone mining in the area, an official said.
The man was injured in an encounter hours after the death of Tauru Deputy Superintendent of Police Surendra Singh.
Singh had signalled a dumper-truck to halt to check documents. But the driver sped on, running over him.
The officer's gunman and his driver jumped aside to safety, but the DSP was hit.
He was rushed to hospital where doctors declared him dead, police said.
Singh, along with his team, had gone to conduct raids to stop illegal mining in Aravalli hills in Pachgaon area near Tauru when he spotted the truck at 11.50 am.
Police teams were deployed to trace the truck and its driver. An official said there was an exchange of fire when the man was tracked down. He was injured in police firing and taken to hospital.
His condition was not immediately known.
Since 2015, about 50 complaints of illegal mining are registered every year in Nuh, officials said. Often, there are run-ins between police and members of the mining mafia.
DSP Singh was recruited as assistant sub inspector in Haryana Police in 1994 and was to retire in a few months. He lived with family in Kurukshetra and hailed from Sarangpur village in Hisar district.