Shivakumar was arrested by the Enforcement Directorate (ED) on Tuesday evening for allegedly being evasive during interrogation. The agency had interrogated the former Karnataka minister for four times in the case.
The 57-year-old leader had earlier asserted that he had not done anything wrong and would fully cooperate with the investigating agency.
Immediately after his arrest, Congress issued a statement condemning his arrest and said the Centre was targeting Opposition leader to divert people's attention from its failures.
A host of Congress leaders have come to their support with Rahul Gandhi saying Shivakumar's arrest was "another example of the vendetta politics unleashed by the government".
Karnataka Congress observed a day-long bandh on Wednesday to protest against his arrest.