A FATAL crash on the M74 in South Lanarkshire is being treated as "potential homicide".

Mark Fleeman, 32, was killed and Lee Allsup, 17, was seriously injured when their white transit van crashed on the northbound carriageway near Larkhall.

The men, both from Staffordshire, were found inside the badly-damaged vehicle at about 4.35am on Thursday.

Police are keen to trace a darker-coloured van which was seen driving at speed near the mens' van.

Det Ch Insp Neil Thomson, of Strathclyde Police, said that initial inquiries "indicate that this may be more than a tragic accident".

"I am appealing to anyone who was driving on the M74 on Thursday morning to come forward if they saw a white van and a darker coloured van, driving at speed, close together, on the northbound carriageway," he said.

"The stretch of motorway which is of particular significance is the northbound carriageway between Lockerbie and the area after the Larkhall on-ramp but before the Hamilton slip road.

"It is vital that people who may have seen these vehicles on that stretch of road come forward.

"The precise circumstances which led to Mr Fleeman's death and the injuries sustained by Mr Allsup have not yet been established. However, this is being investigated as a potential homicide."