Sergeant Tom Findley from Dumfries and Galloway Police told our correspondent Tim Backshall they spoke to witnesses last night but believe there may be more:
"We are aware that early on other vehicles passed the scene and may actually have witnesses it so we're appealing for these people to come forward."
He added that it is unclear what caused the accident at this stage. It is the second fatal on the road in a week.
The A75 is a very busy route it's a main artery in this area and obviously carries a volume of traffic, the more traffic you have then the more likelihood there is of a road traffic collision occurring"
A young child has died following a three car crash on the A75.
It happened at around 5 o'clock at the Hardgrove Cross roads near Carrutherstown. It's the third fatal accident on the road within a week. Local MP Russell Brown has called for the safety of the road to be looked into.
Police are appealing for witnesses after one woman died and another was seriously injured in a crash on the A75. It happened yesterday at around 3pm between Gretna and Annan. It involved a car and an HGV and closed the road for a number of hours while accident investigators
The family of a 19 year old who died in a car accident on the A595 in Cumbria have paid tribute to him.Luke Heywood, who was from Cockermouth, died at the scene of the accident yesterday afternoon. His Peugeot collided with two other vehicles.
His parents and two younger sisters have paid tribute to a wonderful son and brother.
They said: "We love him with all our hearts and we always will. He was always here to help us, a bright light in dark times. He never let us down. He was always here to protect his sisters.
"Luke was gentle, sensitive and loving. He will always be a huge part of our lives and take up a huge part of our hearts. We are lost without him, his smile, his love, his generosity and his deep blue eyes."
A 19 year old man from Cockermouth has died after the car he was driving was involved in a crash on the A595 at Mealsgate near Wigton in Cumbria. Two other vehicles were involved in the accident on Tuesday afternoon. The victim hasn't yet been named.
One person's died on the A595 in a crash late this afternoon. The police say three vehicles were involved in the accident near West Lodge in the Mealsgate area near Cockermouth.