A supply ship has been detained in Scotland for the second time amid claims its crew have not been paid in two months.

The International Transport Workers' Federation (ITWF) has threatened legal action over the Malaviya Seven, which is being held by maritime authorities in Aberdeen.

The same ship was detained in June after it emerged owners GOL Offshore owed £175,000 to sailors who had served aboard its vessels.

The crew were paid in August and the Malaviya Seven, which had been contracted by BP, was allowed to leave port.

It returned to Aberdeen after being hired by another European oil company and was detained on Wednesday by the Maritime and Coastguard Agency (MCA).

A spokesman for the ITWF said: "We have informed GOL Offshore that if they haven't paid all wages by October 15 we'll take a legal position and look to arrest the vessel in the courts.

"Despite the conditions these seafarers have been employed under, oil companies are continuing to use such vessels to maximise profits.

"The industry needs to regulate the employment conditions and start using local labour instead."

Many of the sailors aboard the Malayvia are paid less than the minimum wage, according to the ITWF, taking advantage of a loophole which exempts foreign seafarers from UK employment law.

An MCA spokeswoman said: "We can confirm that the Malaviya Seven has been detained again today in Aberdeen.

"It has been detained due to non-payment of crew wages, expired Seafarers Employment Agreement and no account of seafarers wages.

"The vessel will remain under detention until all these issues have been resolved and only then will it be reinspected."