The transport minister has said that he expects an investigation into the running aground of a ferry on Orkney will look at how it got a safety certificate less than two weeks ago.

Kevin Stewart said that the Marine Accident Investigation Board probe should be completed "sooner rather than later".

Smoke was detected in the engine room of the MV Pentalina on Saturday night before it became grounded near the village of St Margaret’s Hope on the island, leading to the evacuation of 60 passengers, including three children and an infant.

Helen Inkster, managing director of operator Pentland Ferries, said all passengers were “safe and well” when they were evacuated, with the Maritime and Coastguard Agency (MCA) conducting a survey before the Marine Accident Investigation Board (MAIB) are expected on Tuesday.

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The Pentalina had been issued with a passenger ship safety certificate following surveys of the vessel on 18 April.

It came back into service last week to release another ferry, the MV Alfred, to become an 'emergency' ferry to service beleaguered routes on Scotland's west coast that have been hit with disruptions due to breakdowns involving ferry operator CalMac's ageing ferry fleet.

The Herald: Kevin Stewart MSP

Mr Stewart said the award of the certificate would "have to be looked at" by the MCA.

Initial reports suggest the ferry suffered from a “sudden mechanical failure”, according to the MCA.

Mr Stewart said: “Obviously this is a UK reserved matter, the MAIB look at any situation that has occurred aboard vessels, any accident, and I’m quite sure that they will report back to the MCA around about their findings.

“This is obviously of great interest, not only to (the MCA and MAIB), but to the Scottish Government, the likes of Orkney Islands Council and others.

“We have to get to the bottom of what happened here and I hope that happens sooner rather than later.”

Mr Stewart told BBC Radio Scotland that he did "not think it would be the kind of organisation that could be pressurised to be honest with you".

Lib Dem MSP Liam McArthur – who represents Orkney – said that local rumours suggested pressure had been applied to the MCA to deliver a safety certificate to the vessel so another that was previously on the route – the MV Alfred – could be leased to Scottish Government-owned ferry operator CalMac.

The Herald: Pentalina - pentland ferries.

Speaking about the impact of the accident on the route, while the Pentalina is out of service Mr Stewart said that – as of Monday – Northlink Ferries’ summer timetable will be running, including three daily sailings between Scrabster and Stromness.

READ MORE: Kevin Stewart under fire for Scots ferries 'not brilliant' comment

Scottish Conservatives' transport spokesman Graeme Simpson called for an investigation into why the safety certificate was given to the Pentalina just weeks before it ran aground.

“I’m on the same page as the RMT [National Union of Rail, Maritime and Transport Workers]  on this,” he said.

“There needs to be a full investigation into what’s gone on, why was that vessel given approval, only to then break down?”

The MCA os surveying the ferry to assess damage and the Marine Accident Investigation Branch (MAIB) is expected to attend on Tuesday.

Pentland Ferries sails across the Pentland Firth from Gills Bay in Caithness to St Margaret's Hope on the Orkney Islands.

The incident comes after the MV Alfred ran aground in the Pentland Firth in Swona in July last year, with 97 people on board who were transferred to lifeboats.