Staff at a Waitrose fish counter refused to fillet a trout for a customer because it was "too slippery".
In the example of bizarrely excessive red tape, the customer complained to the Health and Safety Executive and Waitrose has since apologised.
According to the Telegraph, the fishy incident follows that of another Waitrose customer who complained that a butcher at a different store had refused to bone a leg of lamb for him. Londoner Stuart Rock said the butcher had said he was able to do the job, but was not allowed due to health and safety.
On its website, Waitrose states: "Waitrose has fish specialists in most of its branches who can advise on what fish to buy. Waitrose fish specialists are trained at London's Billingsgate Seafood Training School.
"Not only can they gut, clean and fillet fish, they also know how to cook every variety they stock."
When the unnamed customer approached the fish counter, an assistant agreed to fillet a whole trout but a supervisor stepped in to say it would not be possible on health and safety ground because the fish were too slippery, the HSE reported.
Poor customer service
The HSE, which has a panel to investigate health and safety myths, said it was an example of "poor customer service hiding behind the health and safety excuse".
It added: "Slippery fish are a fact of life."
"Whilst fish filleting requires the person to know how to us knives safely, it is reasonable to expect this service to be available at a fishmonger's counter in a supermarket especially when the website advertises the service."
Judith Hackitt, chair of the Health and Safety Executive, said: "I'm glad the customer didn't fall for this red herring.
"This is just another case of poor customer service and nothing to do with health and safety."
Waitrose apologised for any inconvenience for both incidents.
Health and safety gone mad
In 2012 the HSE launched the Myth Busters Challenge Panel to encourage consumers to report incidents of extreme health and safety rules.
Common examples of needlessly excessive health and safety rules include cafés and restaurants refusing to warm up baby food for mothers; golfers being told they cannot ride in buggies on a golf course and office workers being told that they cannot wear open-toe sandals.
More bizarre decisions made on health and safety grounds included a school pointlessly relocating a tree house outside of school grounds, and people being banned from sleeping in a camper van on a campsite.
Seven of the craziest supermarket glitches
Waitrose fish monger refuses to fillet trout
One of the most popular glitches, was a wine deal at Tesco back in November 2012, where a series of offers clashed, leaving a bottle of £9.99 wine selling for £1.50.
The 'three wines for £10' deal apparently clashed with a '25% off when you buy six or more bottles' deal. The 25% was accidentally taken off the original price rather than the reduced one, leaving the wine at rock bottom prices. Deal-hunters cleared the shelves around the country.
Perhaps the most popular glitch from Tesco came in June 2011, when instead of taking £4 off the cost of a £20 case of beer, the supermarket accidentally started selling the cases for £4. The ensuring rush was nicknamed the 'beer stampede'.
Sadly not every supermarket pricing glitch comes with such a happy ending for consumers. In March last year the bargain-hunters thought their luck was in, when Tesco accidentally priced the new iPad at just £44.99 instead of around £650. Sadly it spotted the mistake before shipping the goods. The small print on its website meant it could refuse to sell at this price, and refund their customers instead.
In September 2012, Asda was responsible for one of the most expensive glitches. The Asda Price Guarantee offered vouchers to customers who could have got their shopping cheaper elsewhere.
However, when certain trigger products were in the basket, the supermarket massively under-priced the shopping at other supermarkets, and offered huge vouchers to shoppers. In many instances the vouchers came to roughly the same as the cost of the shopping.
In April, a mistake on their website resulted in Tesco selling 8 packs of Bulmers cider 568ml bottles for £5 - rather than a six pack for £8.
Deal-hunters snapped up the deal online, and had varying degrees of success. Some had their order delivered in full, others had six delivered for £5 - and were able to negotiate their way to another two, while others were offered six for £5 or their money back.
October last year saw one of the most famous glitches, when Tesco Terry's Chocolate Oranges were subject to two deals at the same time, and the price dropped from £2.75 to 29p. There were plenty of people getting chocolate oranges last Christmas.
A buy-one-get-one-free deal went awry at Tesco in March. People putting four tubs of I can't Believe It's Not Butter or Oykos yogurt packs into the trolley were only being charged for one.
Soon the online deal-hunting community was in action, with one person bagging 50 tubs of butter and 22 pots of yogurt for £8.79 - a saving of £133.89.