A 1950s tractor described as "a devil" to run was twice started by lightning strikes, according to its owner.
The strikes occurred in Guernsey during a severe thunderstorm on Tuesday, which saw 9mm of rain fall in a few hours.
Owner Horace Camp said two strikes hit the lawn the tractor had been parked on creating an electrical field that had charged his farm vehicle.
He said the tractor was "happily" running by itself and the current must have "given her a good old go".
Mr Camp was inside during Tuesday's storm and only later noticed the Massey Ferguson 35 tractor running.
"After the storm was over I happened to hear the tractor was running, and I couldn't understand why my son would want to do that after there had been such an enormous downfall."
"The tractor was just there alone by itself happily going. It wasn't in gear, so it wasn't moving, but it was happily going," he said.
Mr Camp then tracked down his son, who uses the tractor, to ask him why he was running it in wet weather.
It transpired his son had also been out during the thunderstorm to turn the ignition off.
"It actually started twice during the storm by itself," Mr Camp said.
It is thought the tractor started when an electric charge from a lightning strike hit the lawn the farm vehicle was parked on.
"The tractor had its metal link box touching the lawn so the electricity comes up through that and created a field which connected the starter motor," Mr Camp said.
Lightning theory 'a possibility'
The lightning did not strike the tractor, he added, "but has struck the earth somewhere near and has created a negative electric field on my lawn".
In 1985 a US magazine also reported a farm tractor being started twice by lightning.
Dr Vidyadhar Peesapati from the University of Manchester's High Voltage Laboratory said lightning was known to create an electro-magnetic pulse which has a strong interference, and "maybe could have somehow aided in starting the tractor".
Dr Peesapati said he would need more information, however, to assess the credibility of the claim, and suggested the tractor be taken to the University's specialist lab for inspection.