Why are criminals stealing used cooking oil from Scotland's chip shops?

Police Scotland says organised crime gangs are targeting chip shops, takeaways and restaurants for their used cooking oil.

The liquid is often left in containers outside premises to be taken away to be recycled for potential use as biodiesel, a renewable fuel for transport such as buses and tractors.

Across Scotland, 178 incidents of cooking oil thefts were reported to police between April and October last year.

Grant Cranston said he was surprised by how brazen the thieves who targeted his Inverness chip shop were, adding: "It was broad daylight. There were people walking around."

About 70% of biodiesel produced in the UK is made from used cooking oil, according to UK government statistics.

Prices paid to caterers for their oil can depend on how much is available for collection and its quality, but according to the industry, a restaurant could get about 30p a litre.

On average, thefts of used cooking oil costs the UK Treasury £25m-a-year in lost duty.

Thefts have previously been reported elsewhere in the UK, including in Derbyshire and Gloucestershire.

Police Scotland said the incidents it recorded last year totalled about £20,000 in lost revenue to catering businesses.

Ch Insp Craig Still, area commander for Inverness - where about 20 thefts have been reported between April and October - said the thefts could result in several problems for caterers.

"There is the inconvenience, there is the potential damage caused by the individuals who are entering premises or outside storage to take the oil - and there's also the loss of revenue as well," he said.

"We tend to find there is an organised criminal element in this.

"It's quite often sold on to legitimate oil recyclers who would then manufacture things like biodiesel, which has obviously become more prevalent as technology moves on in relation to production of fuels."

Used cooking oil was stolen from a container outside Hilton Chip Shop in Inverness earlier this month.

Co-owner Grant Cranston told BBC Radio Scotland's Breakfast programme he was alerted to the risk of thefts in the city by a newspaper article.

He said: "So I went on to my CCTV and noticed that the waste oil bin had been slightly moved and I thought 'that's a bit odd'.

"I rewound by about 30 minutes and there was someone stealing the waste oil."

Cranston said the chip shop had been targeted once, as far as he was aware of.

He said the thefts were another problem for his trade to have to deal with.

"Fish and chips at the minute is really, really struggling with rising costs of everything, the VAT, things like that," he said.

Cranston said the industry was trying to play its part in responsible disposal of used oil.

He said: "You put that out there for it to go away and to be recycled, kind of doing your bit for the environment."

Andrew Crook, president of the National Federation of Fish Friers, said some UK chip shops were being repeatedly targeted.

"I think nationally it is a big issue, it's £30-40 per drum," he said.

"If you're going round at night and targeting 10 shops on a regular basis, it's quite a good income for somebody."

Crook added: "One shop said he's lost thousands of pounds because quite a lot of the distributors collect the oil and then they recycle it and you get a credit on your account.

"He lost all those credits because the drum kept disappearing overnight.

"It happened for nine months, so for that business it was a significant impact."

Police Scotland said businesses should ensure oil was stored in a secure and well-lit location, and monitored by CCTV if possible.

Ch Insp Craig Still added: "Our prevention and interventions team is always happy to attend premises and give some advice around building safety and security."