The AAP leader seems to have shifted loyalties ahead of the April 23 MCD polls after triggered a row by allegedly campaigning for a BJP candidate,
The BJP, however, has denied this.
Recently, the video surfaced in which the AAP leader apparently makes negative remarks about Chief Minister Arvind Kejriwal and supports a BJP candidate from a north west Delhi seat, Savita Khatri from Narela.
On Monday, Mr Kumar was allegedly present at the BJP candidate's rally. The Aam Aadmi Party attacked the BJP BJP for "inviting" Mr Kumar to campaign for its candidate.
"BJP has been defaming AAP by taking Kumar's name on radio (commercials). Now, they are even using him in their campaign," Alka Lamba alleged on Twitter.
The BJP said it was the AAP which had "hatched a conspiracy" to defame the saffron party.
"It's a well-planned conspiracy of AAP to harm the BJP's poll prospects at Narela," said Delhi BJP vice-president Rajiv Babbar.
The Delhi BJP spokesperson blamed the AAP for "running a social media campaign to defame" BJP. "We have lodged a police complaint in this regard," said Delhi BJP spokesperson Naveen Kumar.
Sandeep Kumar, a legislator from Sultan Pur Majra in North West Delhi, was arrested last year after a woman who was seen in the video, complained of sexual harassment.
(With inputs from PTI)