Union minister JP Nadda also rejected Prasad's claim of a BJP conspiracy behind his conviction and said the cases were pursued when the UPA was in power and wondered how his party figured in the matter.
He cited other graft cases involving the Congress and its allies, claiming that its alliance was an alliance of "corruption" and it had been exposed badly.
"It has been proved that Lalu Prasad indulged in corruption and the decision has been given by the court. How does the BJP figure in it? It is the alliance between the Congress and Lalu Prasad's party when all such actions have taken place.
Earlier in the day, BJP ally and Union minister Ram Vilas Paswan hit out at Prasad over his public comments before the verdict was delivered, claiming he has been involved in corruption whenever he was in government, including as a railway minister, but was "lecturing" others.
BJP leaders have also cited the recent conviction of former Jharkhand chief minister Madhu Koda, who came to power in an alliance with the Congress, in a corruption case to attack the opposition party.