Talks are being held over claims Northern Isles ferry crews are being paid less than the minimum wage.

RMT representatives are meeting transport minister Humza Yousaf in Edinburgh on Thursday.

Foreign seafarers sailing on ferries contracted by the Scottish Government earn around £4 an hour, the union has claimed.

During a protest in Aberdeen last week, campaigners said ferry operator Seatruck was exploiting its workers.

Mick Cash, RMT general secretary, said: "It is scandal that ships of shame are sailing out of Aberdeen, with workers on poverty rates that make a mockery of our legal minimum wage under a contract that is under the control of the SNP administration.

"This outrage, which is stain on the reputation of the great city of Aberdeen, has to be ended and ended now."

Northlink, which sub-contracted the route between Aberdeen and Shetland to Seatruck, has offered to cover the cost of paying the basic rate of £6.70 an hour.

Seatruck claims giving Northern Isles crews the minimum wage would "distort its fleet-wide pay structure".

Under UK law, it is legal to pay seafarers less than the minimum wage as long as they they are recruited overseas.

Sailors working in Scotland's oil industry are being paid as little as £2 an hour, according to the International Transport Workers' Federation (ITF).

At times more than half of the foreign-flagged vessels working in the North Sea employ crew on less than the minimum wage of £6.70 an hour, the ITF says.

Others are not paid at all, with more than £1.1m of overdue wages owed to foreign seafarers involved in the oil sector this year.

The crew of the Malaviya Seven, which is currently detained in Aberdeen, are due nearly £80,000 and less than a third are paid the minimum wage, the ITF has reported.

Following the protest on Friday, a Scottish Government spokesman said: "The Scottish Government is deeply disappointed that Seatruck has once again rejected Serco's offer to pay their staff the minimum wage and backdate this.

"Scottish ministers are working with stakeholders on the next Northern Isles Ferry Service contract.

"Work is being done to ensure that any future subcontractors pay the minimum wage, regardless of where the company or crew are based."