In the face of a fresh attack by the BJP, ex-vice president Hamid Ansari on Friday said he stands by his previous statement that he never knew or invited Pakistani journalist Nusrat Mirza to any conference.

Mirza has claimed that he had visited India five times during the UPA rule and passed on sensitive information collected here to his country's spy agency ISI. Mirza purportedly commented that he had visited India on Ansari's invitations and also met him.

Ansari, however, has dismissed the charge as a "litany of falsehood".

The BJP on Friday stepped up its attack on the Congress over the matter and cited a photograph of Ansari and Mirza purportedly sharing the stage during a 2009 conference in India on terrorism.

"The former Vice President of India stands by his earlier statement that he never knew or invited Pakistan journalist Nusrat Mirza to any conference, including the 2010 conference mentioned by Nusrat Mirza or 2009 conference on terrorism or on any other occasion," a statement from Ansari's office said.

Rebutting the BJP's claim of inviting Mirza, Ansari had a couple of days earlier said it is a known fact that invitations to foreign dignitaries by the Vice-President of India are on the advice of the government, generally through the Ministry of External Affairs.

Clips of Pakistani journalist Mirza's interview in Pakistan have been doing the rounds on social media for the last few days in which he stated that he attended a seminar on terrorism in India in which Ansari spoke.

Mirza also claimed to have given secret and classified information to the Pakistani spy agency Inter-Services Intelligence (ISI).