BJP leader Ganesh Joshi, accused of assaulting a police horse during a protest rally earlier this week, was arrested on Friday, the Uttarakhand Police said.The white horse 'Shaktimaan' is alive but his injured leg has been amputated, police added.Joshi, the legislator from Mussoorie who has professed innocence, was arrested outside a Patel Nagar hotel following an FIR against him. Senior police officials told IANS that the legislator was being questioned in the case.Dehradun district police chief Sadanand Date said Joshi was responsible for the injury to the hind legs of the horse belonging to police cavalry.The Bharatiya Janata Party (BJP), the principal opposition in the state, has hit back by describing the police action as "illegal".Joshi allegedly attacked and severely injured Shaktimaan during a protest against the Harish Rawat government in Dehradun on Monday.