Trader Saurabh Mehrotra has been jailed for a year in a case relating to a crude oil deal that ended up in London arbitration.
The son of London-based shipowner Ravi Mehrotra was sent to Pentonville prison in London in April on the order of a High Court judge after failing to provide enough documentation in the case.
In an October hearing, Mehrotra had pledged to repay $6m for which he acted as guarantor, following a court order last June.