Senior party leader and AAP's Delhi convenor Ashutosh said that party's funding was transparent in nature and that for the past few days rival parties had been making allegations over the funding.
He said AAP is in the process of preparing a list of people "notorious" for making such claims.
It has also challenged the BJP to reveal its sources of funds.
"The central government's submission in the Delhi High Court on Wednesday that it had not found any source of foreign donations to the Aam Aadmi Party is a slap on the face of the BJP, particularly its Delhi unit.
"The party will file a criminal defamation suit against people levelling such allegations. The message the party wants to give is that when you talk, please do that with proof," Ashutosh added.
Accusing AAP of diverting funds from NGOs of its leaders, Delhi BJP had called for a probe into such events.
"Due to lack of transparency, common man is wondering whether donation is being received at the rate of Rs 20,000 per plate or the funds of NGOs, which belonged to AAP leaders, are being diverted," Delhi BJP general secretary Ramesh had said in a press conference.
Reacting strongly after the news conference, AAP chief Arvind Kejriwal had threatened to file a defamtion suit against the BJP.
