Mr Singhal, who is contesting from ward number 59 N in Rohini, alleged that as soon as he left the polling booth, he was attacked by some Congress workers which left him seriously injured.
Mr Singhal is currently in hospital. His statement is being recorded, said the police.
"The statement of the victim is being recorded. He underwent a medical examination but there were no visible signs of injury," said the police to the Press Trust Of India.
Swaraj India's spokesperson Anupam tweeted:
Congress Candidate from Ward 59N Rohini badly beats up the Swaraj India Candidate Sanjay Singhal. Heavy mobilisation at Sector 7 Police Stn.- Anupam (@AnupamConnects) April 23, 2017
Swaraj India, led by activists Yogendra Yadav and Prashant Bhushan, made its electoral debut with the MCD polls. Both Mr Yadav and Mr Bhushan were a part of Arvind Kerjiwal-led AAP.
About 54 per cent people had turned up to vote today, which is almost the same figure as the last elections in 2012, when 53.9 per cent polling was recorded.
(With Agency inputs)