A team from Hauz Khas Police Station is looking into the matter.
The brother of a Delhi Police sub-inspector was allegedly attacked by another policeman over a parking dispute on Saturday evening in south Delhi's Shahpur Jat area, police said.
Suraj Bhan, a constable, allegedly attacked Gajendra, a property dealer, they said.
Suraj used to park his cars outside Gajendra's house in Shahpur Jat and the latter had warned him against it. However, Suraj didn't listen to Gajendra and they allegedly had a fight over the issue on Saturday.
Both of them were taken to hospital for a medical examination, a senior officer said.
A team from Hauz Khas Police Station is looking into the matter.