A port operator has been fined £650,000 over health and safety breaches after the sinking of a tug boat which claimed the lives of three crewmen.

The Flying Phantom capsized in thick fog almost seven years ago while towing a cargo vessel on the River Clyde near Glasgow.

The incident happened six days before Christmas in 2007 when the tug ran aground in the Clydebank area of West Dunbartonshire.

Captain Stephen Humphreys, 33, and Eric Blackley, 57, both from Gourock, Inverclyde, died along with Bob Cameron, 65, from Houston, Renfrewshire.

A fourth man, Brian Aitchison, 37, from Coldingham in the Borders, was rescued after he managed to swim free and cling to a buoy.

Port operator Clydeport Operations Limited was fined during sentencing at the High Court in Edinburgh today after pleading guilty to health and safety breaches at a hearing last week.

The operator of the tug, Svitzer Marine Limited, last year admitted a series of health and safety breaches and was fined £1.7 million.

It emerged that the Danish firm had failed to act after a similar incident involving The Flying Phantom in December 2000.