In its affidavit filed before the court, the police said that the congregation was allowed only for yoga camp and for no other purpose.
It further said permission was granted only for a gathering of 5,000 people but on the intervening night of June 4 and 5, more than 20,000 people had gathered at Ramlila ground.
The police submitted in court that it resorted to lobbing tear gas shells only after followers of Ramdev started pelting stones at police personnel.
The response of the police came after the court took suo motu cognisance of the crack down.
The court had issued notices to the Union Home Secretary, Delhi Chief Secretary and the Delhi Police Commissioner, and had asked them to respond within two weeks about the circumstances that led to the operation.