In the notice, Yadav asked Modi either to tender a public apology for this within one week or be prepared to face a criminal and civil case.
The notice served to the BJP leader by Yadav's lawyer Murari Kumar threatened to lodge a defamation suit of Rs one crore against him.
It said that Yadav is presently a member of Lok Sabha from Madhepura after defeating a political stalwart (Sharad Yadav,JD(U) President) and has been member of Parliament several times.
Sushil Modi, who is leader of opposition in Legislative Council at present, has been describing Yadav as a man of criminal background in interviews and comments in media which has been denting image of the MP, the notice, a copy of which was made available to mediapersons, said.
The RJD MP alleged that he has been undergoing mental stress due to sustained "sinister" campaign of Sushil Modi against him.