Kumar, a 1985 batch officer, along with former Haryana Chief Minister, Om Prakash Chautala, his MLA son, Ajay Chautala and 53 others was earlier convicted by a Delhi court for illegally recruiting 3,206 junior teachers and was out on parole.
He was arrested along with alleged gangsters Shoukat Pasha and two shooters Taufiq and Manna, police said.
"Sanjiv Kumar has been arrested for criminal conspiracy to murder a businessman, who is his friend and closest associate. The plan was hatched while in Tihar Jail when Sanjiv was in judicial custody along with the Chautalas," said a senior police official today.
He wanted to eliminate his close friend with whom he had developed some property disputes and also wanted to get himself injured and get bail, the official said.
"And most importantly he wanted to blame the Chautalas for this attack on himself and his friend," the police official said. Kumar was earlier director of Primary Education and the court had relied on his testimony for the verdict.
He was initially a whistleblower in the case but in the CBI probe that followed he was also found to be involved in the scam.