The Enforcement Directorate (ED) questioned Congress leader and former Nilambur Municipal Council chairman Aryadan Shoukath on Wednesday.
The interrogation was based on the statement that Shoukath had assisted Nilambur Mary Mata Educational Trust chairman Sibi Violin, accused in an education financial fraud case.
The interrogation started at 11 am at the ED unit office in Kalla and lasted till 9 pm.
Sibi Vayal, a native of Thiruvambadi, was arrested by the police last November in a case of extorting money from students by promising them seats for MBBS studies in Kerala and abroad.
Sibi, who contested as an independent candidate in the Wayanad constituency in the last Lok Sabha elections, claimed to be the director of the Food Corporation of India (FCI).
The vehicle bearing the official seal of the FCI was used during the election.
Following the receipt of the complaint, the police conducted an investigation and found that the claim that he was an FCI director was false. The case and the financial fraud case were handed over to the ED.