The Aam Aadmi Party (AAP) leader had come with members of the Narmada Bachao Andolan (NBA) to the Indian Women's Press Corps (IWPC).
As the conference began, a young man identifying himself as Vishnu Gupta and chief of Hindu Sena entered the conference room and raised slogans against Bhushan.
He urged Delhi Chief Minister Arvind Kejriwal to throw Bhushan out of the country.
Gupta was also carrying a letter to Kejriwal written in Hindi that the group was "nationalist not terrorist".
The letter said Kejriwal should take back the cases against Pinky Chaudhary, president of another Hindu group, and 12 other people involved in the attack on the AAP head office in Ghaziabad Jan 8 to protest Bhushan's controversial remarks on army deployment in Jammu and Kashmir.
AAP volunteers guided the man out and closed the main gate of the IWPC. By then, the press conference got disrupted.
Police said they were looking for a complaint from the AAP.
Chaudhary and the other 12 people were arrested by Uttar Pradesh Police for attacking the AAP office. They are still in custody.
--IANS (Posted on 13-01-2014)