Convenience stores' losses from shoplifting tripled last year to hit a record high, according to the industry.
The Association of Convenience Stores (ACS) came up with a total of £131m, based on estimates from 7,123 shops in England, Scotland and Wales.
The findings, seen by BBC Radio 4's You and Yours, show an average annual loss per store of £2,605.
Retailers say the police response is inadequate, with one store owner installing bicycle chains on fridges.
"It is possible that some companies have previously underestimated theft levels in their business," the ACS admitted to the BBC.
But it added: "A lot of businesses have seen their theft levels double."
Some of the Association's members are seeing lots of items stolen in one go.
That would help explain the discrepancy with government data.
While shoplifting in England and Wales is at its highest level on record, with a 5% rise last year to 349,296 reported incidents, those official figures do not reflect the value of goods stolen.
After losing £12,000 to theft last year, Coventry shopkeeper Paul Cheema told You and Yours he had resorted to desperate measures.
"One man took 32 packs of bacon and 20 packs of cheese," he said.
"So we put bicycle chains and doorbells on our fridges so every time a door opens an alarm sounds.
"We're also using social media to post pictures of suspects."
West Midlands Police told the BBC: "We take reports of shoplifting seriously and our figures show that we solve more than 50% of reported incidents in Coventry."
But Mr Cheema claims the police lack the resources to deal with the problem.
Some 71% of retailers surveyed by the ACS also said they were dissatisfied with the response of police to reports of theft.
"These guys have got inner coats and inner pockets, they do what they need to do," said Mr Cheema.
"There's a bigger picture behind this. They are not just nicking this amount of food to eat at home.
"Are the police to blame? There's only a few officers for the whole of this area. The government needs to do more to support local businesses."
ACS Chief Executive James Lowman shares the concerns of his members.
"Police forces are de-prioritising shop theft as they have so many other challenges. We think that's the wrong priority.
"Shop theft, for the most part, is either part of organised crime or due to alcohol and drug addiction. That's why it's really important that police do intervene."
The National Police Chiefs' Council defended its members' record on crime and urged shop owners to do more.
"We recognise the importance of listening to all businesses," the council's lead for business and retail crime, Craig Mackey, told You and Yours.
"A new National Business Crime Reduction Hub will work closely with all forces and businesses to reduce crime.
"We encourage all businesses to sign up to the their local policing Twitter accounts," he added.
The Home Office said it was also working with retailers to tackle the problem.
"Retail crime harms businesses, consumers and communities and has no place in a Britain that works for everyone," a spokesman said.
He added: "It is for individual forces to decide how to allocate resources."
You and Yours is on BBC Radio 4 weekdays 12:15-13:00 GMT. Listen online or download the programme podcast.