Freightliner runs the most of the haulage on British railway networks.
Thai police also arrested Pettit in connection with 42 methamphetamine tablets, sex toys and pornographic DVDs they said they found at his rented condominium.
Two days after he was arrested last March as part of an ongoing operation Thailand's DSI also arrested a Buddhist monk and his accomplice, who, police said trawled hill-tribe villages looking for young boys to supply to foreigners.
Freightliner coal train -freefoto.com
At the time Thai police said Pettit had a 'history' of child sexual abuse in Britain.
It is not clear how he obtained bail on the charges.
An FCO spokesman said: "We can confirm the death of a British national in Laos on 18 February.
The Australian Embassy in Laos has been assisting us with this case. We have been in touch with the family and are providing consular assistance."
Britain does not have a mission in Laos.