Authorities have reported that 95-metre (312-foot) superyacht Indian Empress has been impounded in Malta after its crew demanded payment of back wages to the value of more than one-million U.S. dollars.

The superyacht, owned by multi-millionaire Vijay Mallya, was boarded by port officials in Valletta and prevented from leaving Malta as part of the crew’s legal action to recover unpaid wages.

The mariners’ union Nautilus International confirmed more than 40 crewmembers have not been paid since September 2017 when Mallya, who is fighting extradition from the UK to India, abandoned the vessel.

The latest development is part of a landmark case that could see the financial security provisions of the Maritime Labour Convention enforced in the superyacht industry for the first time.

Described as a safety net for anyone working at sea, the convention was used to secure an initial payment of $615,000 last month via the Norwegian protection and indemnity insurance specialist Skuld. The yacht will be held in Malta under a “maritime lien” until the remaining wages are paid.

Mallya is in Britain pending extradition proceedings initiated by India. He stands accused of fraudulently deflecting losses from his now defunct Kingfisher Airlines onto banks by taking out loans he had no intention of repaying. Mallya denies all wrongdoing.

Launched by Oceanco in 2000, Indian Empress offers accommodation for up to 12 guests and 30 crewmembers. Registered in the Isle of Man, she is estimated to be worth 93 million U.S. dollars.