Mr Nikam's arrest came just hours after his party promised action against him.
"We can't tolerate a senior citizen being slapped. Raj Thackeray was upset seeing the visuals," said Akhilesh Chaubey, General Secretary (Legal), MNS.
65-year-old DG Patil had taken up a contract for repairing a water pipeline in Kalyan (East); he works as a private contractor with the Kalyan-Dombivli Municipal Corporation (KDMC).
According to reports, Mr Nikam summoned Mr Patil following complaints about delays in the water pipeline repair work in Kalyan's Ganeshwadi locality that caused water scarcity. Then, in full public view, apparently unhappy with the work done by Mr Patil, the MNS corporator assaulted the 65-year-old. (Watch)
"There's no water supply in Kalyan-East for the past four days, and the officials and the contractors were passing the buck between themselves. They do not understand decent words the message was delivered in our style, and we hope to have water tomorrow," Mr Nikam said on Sunday, seemingly proud of his actions.
"There was a leakage in the pipeline. I had gone there to fix it but instead of talking to me started hitting me," said Mr Patil.
An engineer, who was supervising the repairs, was present when the incident took place.
"The work was getting delayed that is why Nitin Nikam got angry and he slapped one of the workers of the contractor. We are going to investigate into the matter and make sure the guilty is punished," said Ramnath Sonawane, Commisioner, Kalyan Dombivli Municipal Corporation.
The police has yet to make an arrest even though Mr Patil has lodged a police complaint at the Bazaarpet police station in Kalyan.