Assistant Police Inspector Sachin Suryavanshi, who is in hospital, told NDTV that yesterday, he pulled over the official car of Kshitij Thakur, an MLA from the Bahujan Vikas Aghadi. Mr Thakur was in the car at the time.
This morning, the police officer was summoned to the Assembly today to explain his action.
Mr Thakur in the Assembly accused the policeman of breach of privilege and said he had been abused by the cop.
Enraged by his account, members cutting across party lines demanding that the official be suspended.
Mr Suryavanshi was seated in the visitor's gallery.
The legislators - including an independent, a member of Raj Thackeray's Maharashtra Navnirman Sena (MNS), a third from the Shiv Sena and also several others - then grabbed the policemen and allegedly slapped and punched him.