Immigration officials on Thursday detained a key aide of former Jharkhand chief minister Madhu Koda at Mumbai’s international airport. The aide, Arvind Vyas, was taking a flight to Dubai. Vyas, an alleged hawala (transfer of money through illegal channels) operator who was supposedly instrumental in transferring abroad around Rs 1,500 crore belonging to Koda, was detained along with some others in the morning.

Koda, who was Jharkhand chief minister from 2006 to 2008, is alleged to have salted away money abroad. A senior immigration official confirmed the detention. Vyas is a key person in the investigation against Koda.

During the initial questioning by the income tax (I-T) and Enforcement Directorate (ED) in November last year, he had reportedly confessed to have arranged to have delivered $1 million to Sanjay Choudhary, who oversaw Koda’s operations in Dubai.

However, after that Vyas did not respond to any of the summons issued by the ED. “He was not traceable,” a Delhi-based ED official said, adding “his further questioning would make our case more strong”.

Immigration officials handed over Vyas to the Directorate of Revenue Intelligence (DRI), which along with ED officials, grilled him till late evening.

DRI Additional Director General (Mumbai) T. K. Govil refused to comment on the matter. The DRI is also investigating import-export cases of the Balaji Group, in which Vyas was a director. The group, owned by Manoj Punamiya, had through its various companies allegedly transferred Koda’s money abroad. The I-T and ED questioned Punamiya last year.