Authorities in Gibraltar have fined the captain of the bulker responsible for last month's bunker fuel spill, while ship manager Anglo-Eastern has paid £1.5m ($2.1m) for clean-up costs.

Captain Ashish Maini, a 43-year-old Indian national and the master of the 93,200-dwt AM Ghent's (built 2011), was fined £20,000 in the British overseas territory's Magistrates Court on 5 March, the Gibraltar Chronicle reported.

The fine came after Maini plead guilty to charges including allowing oil to be discharged into port waters and damaging the breeding ground of a European protected species.

"Other than incidents which involve loss of life, an oil spill is the worst thing that can occur at sea, it is a captain’s nightmare," Maini's attorney, Freddie Vazquez, reportedly said in court, while reading a statement from the captain.

The AM Ghent was in the Bay of Gibraltar on 12 February when a botched refuelling operation caused by a faulty valve spilled bunker fuel into the port.

Initial reports said 1,000 litres of fuel was spilt, but reports now suggest as many as 2,000 litres ended up in Gibraltar waters.

In court, Vazquez said the spill was down to an "unforeseeable breakdown in a pipe".

"The crew can bear no blame, everything had been done as it needed to be done and unfortunately accidents happen," he said.

"The ship had taken fuel weeks earlier and the valve worked well and then in Gibraltar it inexplicably faltered."

The ship's technical manager is Anglo-Eastern and it is owned by commodities trader ArcelorMittal.

Anglo-Eastern did not immediately respond to a request for comment from TradeWinds. Its payment was divulged in court by Vazquez, the Gibraltar Chronicle report said.

In the aftermath of the spill, ArcelorMittal said it was working with the manager and the Gibraltar Port Authorities to coordinate clean-up efforts.

The ship was also detained by Gibraltar authorities, though it appears to have been released as AIS data shows it sailing in the north Atlantic to the US.