If Mr Tomar had done any wrong, Mr Kejriwal said he would have surely asked him to step down.
"I am not Tomar's relative or friend. I had sought an explanation from Tomar on the controversy. He gave a satisfactory answer and said he wasn't at fault as his degree is genuine," Mr Kejriwal said.
He said a Right to Information query seeking details about Mr Tomar's law degree from a Bihar university was moved on a wrong roll number. "It was done to taint his image," Mr Kejriwal claimed, while speaking at the launch of a multimedia web site in Delhi.
"There is a need for a public trial of the media to expose their bias," he said.
"A section of the media has tried everything to tarnish the Aam Aadmi Party's image," he said, adding some media houses were conspiring against his party.
"Why did not television channels highlight issues related to (Surface Transport Minister Nitin) Gadkari but leave no stone unturned to showcase AAP issues? We need transparency in the media."
"In retrospect I think we should have cancelled the event after Gajendra hanged himself."
Mr Kejriwal, who became chief minister in February after leading the AAP to a sweeping win, said that better governance in Delhi was his main agenda.
He added that Delhi won't face water and power shortages this summer.
"We have taken necessary steps to ensure adequate water and power supply for the residents of the national capital this summer."