The police said India Against Corruption (IAC) had informed the police about the protest after which they were made to sign an undertaking before granting Team Anna the permission.
Rajan Bhagat, PRO, Delhi Police said that since Section 144 was not imposed at Jantar Mantar, Anna Hazare was given permission to hold a day-long protest.
In a meeting held on Thursday, Dec 9 between Team Anna members and the Joint Commissioner of Special Branch, Delhi Police, the IAC organisers were told not to hold a gathering of more than 7,000 people, as this was the capacity of the ground.
Organisers were also instructed about Anna's security.
Anna Hazare decided to go a day long fast following the government's delay in coming up with a strong Lokpal Bill.
Meanwhile, the Parliamentary Standing Committee will table the Lokpal draft in Parliament today.