The case against Mr Alam and his aide is related to the alleged Jharkhand tender scam.
Jharkhand Rural Development Minister Alamgir Alam has been arrested by the Enforcement Directorate in a money laundering case linked to the seizure of over Rs 35 crore in cash from a flat linked to his personal secretary and the latter's house help.
Mr Alam was questioned for over nine hours at the Enforcement Directorate office in Ranchi on Tuesday and he was called again on Wednesday. He was interrogated for six hours and was arrested for not cooperating with the investigation, ED sources said.
The agency had raided a 2BHK flat in Ranchi occupied by Jehangir Alam, a house help of the minister's Personal Secretary Sanjiv Lal, last week and recovered Rs 35.23 crore from there and an additional over Rs 1.5 crore from other premises. A total of Rs 37 crore was seized.
Mr Lal and Jehangir Alam were arrested under the Prevention of Money Laundering Act (PMLA) the next day and are currently in ED's custody.
The case against Mr Alam and his aide is related to the alleged Jharkhand tender scam, under which commissions were collected and then distributed under Mr Lal's supervision.
The 70-year-old Congress leader was first elected to the Jharkhand Assembly in 2000 and has also served as its Speaker. His arrest comes months after Jharkhand chief minister and Jharkhand Mukti Morcha leader Hemant Soren was taken into custody by the ED in the land scam case. Mr Soren had resigned as the chief minister just before he was officially arrested.