A huge blaze which took 30 firefighters 12 hours to bring under control was started deliberately say police.
The fire broke out at a compost slab behind the Kinneil Kerse recycling centre in Grangemouth Road, Bo’ness shortly after 7pm on Monday.
The flames raged through the night and fire crews were still at the site, which is run by Falkirk Council, at 11.30am on Tuesday.
The Scottish Fire and Rescue Service said six appliances were in attendance using high-powered hoses on the affected area.
A Scottish Fire and Rescue spokesman said: “At 7.40pm on Monday, September 18 the Scottish Fire and Rescue Service was alerted to reports of a compost pile on fire at Kinneil Kerse recycling facility in Bo’ness.
“At its height, six appliances attended and extinguished the fire using high-powered hoses. Crews remain at the scene and continue to dampen down the affected area which is approximately 40 metres by 40 metres.”
A source told The Falkirk Herald machinery which processes the compost was tampered with, prompting the police investigation into wilful fire-raising.
Police say the fire caused around £4000 worth of damage and are appealing for witnesses to come forward with information.
A Police Scotland spokesperson said: “Police Scotland are investigating following a suspicious fire in Bo’ness.
“The incident was reported around 7pm on Monday, September 18 at a recycling facility in Grangemouth Road. The Scottish Fire and Rescue Service were in attendance and extinguished the fire.
“Inquiries to establish the full circumstances are ongoing and anyone with information is asked to contact Police on 101, quoting incident reference 3707 of September 18.”
A council spokesman said: “We were alerted around 8pm (Monday) to a report of a fire at Kinneil Kerse recycling centre.
“On further investigation, the fire was at our composting slab, used for garden waste, that lies around 50 metres away from the main recycling area and facilities.
“Scottish Fire and Rescue have been on site throughout the night dealing with the incident.”
The fire did not affect the main recycling site which remained fully open to the public, with all facilities operational throughout the day of the fire.