Karti, 46, was placed under arrest by a CBI team on his return from London.
The law minister said that the nature of evidence available against the offender must speak for itself and not the "alibi" of vendetta.
"The law is taking its course. The law must take its course. The CBI will explain all the details. We do not wish to interfere. There is no interference of the government," he told reporters.
"But I will only make one observation. When such issues are raised, what is important is that the nature of evidence available against the offender must speak for itself and not the alibi of vendetta," he said.
The Congress Wednesday dubbed the arrest of Karti Chidambaram a "diversionary tactic" by the government to hide its scams and said "vendetta" would not deter the party from speaking the truth.