Activist Yogendra Yadav was taken to the Parliament Street police station (Picture tweeted by @_YogendraYadav)

I have been beaten up, manhandled, dragged, pushed and arrested at the parliament street police station. pic.twitter.com/kbJgT9rSuh - Yogendra Yadav (@_YogendraYadav) August 10, 2015

I have been dragged, hit and pushed into a police van. Don't still know my crime. - Yogendra Yadav (@_YogendraYadav) August 10, 2015

Been brought to park street police station alone itch others - Yogendra Yadav (@_YogendraYadav) August 10, 2015

Activist Yogendra Yadav was detained by the Delhi Police late on Monday night from the site of a farmers' protest at Jantar Mantar in New Delhi. Mr Yadav, a former leader of the ruling Aam Aadmi Party, alleged that he was "beaten up, manhandled" at the police station and was arrested.Tweeting a picture of himself with a torn sleeve as proof of his allegations, the 51-year-old said,The activist, who founded the Swaraj Abhiyan alongwith lawyer-activist Prashant Bhushan, alleged that he had rushed to Jantar Mantar after learning about reports of a police crackdown on farmers who he said were holding a "peaceful" protest at Jantar Mantar. Mr Yadav alleged that he was later bundled into a police van along with other demonstrators and taken to the police station.He also tweeted:Mr Yadav has been leading a protest by farmers from Punjab, Haryana and Rajasthan against the controversial amendments to the land acquisition bill.They had led a 'tractor protest' till the Delhi border at Kapsahera on Sunday night, where police had prevented the tractors from entering the city. The protesters had continued on to Jantar Mantar, in the heart of New Delhi to carry out the protest.