Yogendra Yadav, former AAP leader and founder-member of farmer rights group Swaraj Abhiyan, was arrested on Tuesday. He said he was "dragged and hit", a charge which the police denied.
Yadav and many fellow activists of the group were arrested around 1 am from Jantar Mantar, where they held a protest, demanding adequate compensation for farmers affected by the land bill as well as those hit by crop loss.
Yadav's aide Anil Kumar Maurya told IANS that they had taken prior permission from the Delhi police commissioner to hold the protest till Monday and were told the permission may be extended.
However, police said Yadav was permitted to hold the protest on Sunday and Monday only and Yadav continued his protest early Tuesday without permission.
Deputy Commissioner Police Vijay Singh told IANS that when police asked Yadav to end his protest, he wrote another letter to police asking for permission to continue his protest till Friday, the eve of Independence Day on August 15.
"Considering the Independence Day and the terror threats, we did not allow him to continue the protest. But he challenged the police and continued his protest. Later, he was arrested and kept in parliament street police station," Singh said.
Singh said that allegations made by Yogendra Yadav were false. "There was no manhandling. Our police officers only tried to persuade them to end their protest. The protestors were not beaten up."
Singh said Yadav and 85 other protesters will be kept in custody till Tuesday evening as they threatened to march up to the prime minister's house.
But Yadav insisted that he was manhandled by police. "I have been dragged, hit and pushed into a police van. Still don't know my crime," he tweeted.
Yadav's aide Maurya said they were holding "a protest outside the police station since 2 a.m. after Yogendra Yadav was arrested".
Delhi Chief Minister Arvind Kejriwal also took to Twitter and condemned the police action.
"I strongly condemn the treatment meted out to Yogendraji by Delhi Police. They were protesting peacefully. It is their fundamental right," he said.