Type of controlled burn known as swaling could be to blame for Dartmoor gorse fire
It was declared a major incident and scrambled crews from Devon and Cornwall
It is believed a type of controlled burn known as swaling could be to blame for the gorse fire on Dartmoor that was declared as a major incident.
It is one possible cause being considered after the blaze near Yelverton on Tuesday.
At its height, crews from 13 stations across Devon and Cornwall were fighting the flames.
Thick smoke brought traffic to a standstill and businesses like the Dartmoor Diner had to be evacuated.
Devon & Somerset Fire & Rescue Service says investigations into the exact cause of the fire are ongoing.
However, Group Commander Matthew Head has issued a plea for people using the moor to be sensible.
He said: "The police are looking into the cause of the fire. Obviously we've had a lot of swaling recently that has, in the past, got out of control but we've not confirmed if that is the case.
"Common causes of fire are things like people barbecuing and lit cigarettes on the moor".
He added: "I would encourage everybody over this lovely spring and summer that we're hopefully going to have, if you are going to use barbecues - please do avoid it if you can - please make sure you extinguish them and you are taking them with you".
At one point, the smoke was so thick it completely shrouded the main A386 which had to be closed.
In a statement at the time, Devon & Somerset Fire & Rescue Service said: "This afternoon fire crews attended gorse fire on Dartmoor in the area of Clearbrook.
"At the height of the incident there were 11 pumping appliances tackling multiple seats of fire across a large area of approx. 950 acres.
"We also mobilised three of our all-terrain vehicles to help access the fire spread as well as a water carrier to help with water supplies in the rural area.
"Crews made steady progress getting the fire under control in a relatively short space of time".
They later added: "Crews worked closely with the police to ensure fire spread was contained, utilising the police helicopter and drone".