THE family of a schoolgirl who was killed in a school bus crash have accused the coach driver of causing the accident and trying to mislead police about it.

Relatives of Natasha Paton, 17, have urged a sheriff to find the standard of Raymond Munro's driving was the most likely cause of the tragedy.

They said he was travelling too fast for the wintry conditions when the bus collided with a bridge on the A73 near Biggar and tumbled down an embankment into a river.

The family also told a fatal accident inquiry Mr Munro, 63, had made false statements to police to deflect blame.

Gordon and Jacqui Paton were devastated when Natasha died on a trip taking 39 pupils and staff from Lanark Grammar School to Alton Towers theme park in March 2010.

In a written final submission to the inquiry, the family's solicitor David Wilson said: "The cause of the accident is clearly down to the failure of Raymond Munro to take reasonable precautions on the approach to the bend at Wiston Bridge.

"The speed of the vehicle and the application of brakes in snowy and slushy conditions was the cause of a loss of traction as he was negotiating the bend, causing the vehicle to career head-on into the parapet of Wiston Bridge and thereafter fall into the Garf Water.

"He was familiar with the route and was aware of the upcoming 90 degree bend.

"A driver taking reasonable precautions would have been able to reduce speed sufficiently on the approach to Wiston Bridge to negotiate the bend without losing control."

The family asked Sheriff Nikola Stewart to disregard claims made by Mr Munro in a police interview, in which he said there was black ice on the road and he had warned teachers not to go ahead with the trip.

Mr Wilson added: "From the uncontested testimony of the adult helpers and teachers, it is clear this warning was never given.

"I would submit the claim of the existence of black ice is only consistent with an attempt by him to mislead the police and to deflect blame for the catastrophic crash on to other parties, namely the teachers and South Lanarkshire Council."

Mr Munro's legal team also asked the sheriff to disregard his interview but said he did not accept responsibility.

His lawyer Barry Smith said: "It is accepted by Mr Munro that a reasonable precaution whereby the death might have been avoided was to travel at a lower speed at the accident locus. That is not accompanied by a concession that he should have travelled at a lower speed."

The Crown Office asked the sheriff to find the accident could have been avoided if Natasha had worn a seatbelt and Mr Munro – from Bothwell, South Lanarkshire – had slowed down at the bend before the bridge.

The inquiry has closed and Sheriff Stewart has retired to consider her determination.