The man identified as Vishnu Gupta, who claimed to be the president of Hindu Sena, shouted slogans against the noted lawyer and called him a "traitor" for his recent comments relating to army's presence in Kashmir.
Last week, Prashant Bhushan had said that deployment of military in Jammu and Kashmir should be undertaken with the consent of people of the state. His comment was slammed by parties across the political divide. Aam Aadmi Party chief Arvind Kejriwal had also disapproved of Prashant Bhushan's comments.
Incidentally, the AAP office in Kaushambhi was vandalised by around 30 activists of Hindu Raksha Dal last week in response to Prashant Bhushan's statements, which the lawyer said were "twisted" by the media.
The drama today lasted for 10 minutes. In the meantime, AAP volunteers called up police, which reached the venue just before the press conference ended.
Gupta managed to escape, but only after speaking to the media. It is also believed that he was a part of the group that vandalised the AAP office.
In an unsigned statement handed over to the media, Gupta claimed that Kejriwal had invited them for a debate, but on the other hand, he pressed false charges against Pinky Choudhary, national convenor of the Hindu Raksha Dal, who along with his supporters vandalised AAP office in Kaushambhi last week.
He also also demanded that Arvind Kejriwal clear his party's position on Kashmir and other issues.
"This shows the desperation and culture of big parties like the Congress and the BJP," Prashant Bhushan told the reporters after the incident.