This is the shocking moment a barman found a live RAT emerging from one of the pub's toilets.
The worker, who wishes to remain anonymous, was starting his shift when he went into the gents loos and saw the rodent crawling up the inside of the cistern.
He recalled in horror at seeing the rat inside the filthy toilet - taking out his phone to record the incident to show to his boss.
The owner of the Folly bar in Boston, Lincs., has claimed the sighting of the rat was an isolated incident.
But former employee Emma Carpenter slammed the 'disgusting' conditions, labelling the toilets as a 'breeding ground'.
Emma, 32, who now works in another bar in Boston, Lincs., said: "My colleague was opening up when he went into the gents and saw the rat in the toilet.
"He was horrified, it's just not the sort of thing you would expect to see. It's like something from a third world country.
"You can tell from the state of the toilet that it's riddled with germs.
"The bar's owner tried to claim it was because the toilets hadn't been cleaned the night before but this is months of filth.
"It's unsanitary, vile and disgusting. He's putting the public's health at risk."
Following the incident last month, pest controllers were called to the bar where they fitted rodent barriers in the drain.
They also advised rooms needed clearing out beneath the toilets to help deal with the rat infestation.
Matt Clark, who owns the bar, said he was aware of the pictures.
He said: "I was aware of an isolated incident. He [pest control] did confirm it was an isolated incident and there was no evidence of concern.
"He went away quite happy with no recommendations.
"We will continue with our normal pest control advice from our contractor - that's what we were told to do.
"We are very close to a river and rodents can find their way around.
"The pest controller has installed one way valves into the system.
"It's unfortunate that this has raised it's head.
"The pest controller's opinion is that it is just an isolated incident - we couldn't do anything to stop it."
Andy Fisher, Head of Housing, Health and Community Services at Boston Borough Council, commented:
“With the consent of the owner, the Council can confirm that a complaint was received (12 March 2018), about an incident that occurred on 16 February 2018. In line with our standard approach, the Council contacted the owner and met with them on site today.
"Evidence was presented that shows a pest controller was called out immediately by the owner; the controller removed the rodent and installed additional equipment to prevent any access through the foul drainage system.
"Environmental Health Officers undertook a thorough inspection of the premise and found no evidence of rodent activity anywhere. The Council is satisfied that the owner took swift and appropriate action as soon as the issue was discovered and that there are no pest problems at the premises.”