Some of the UK's biggest electricals retailers are offering so-called discounts that deliver little or no real savings, a consumer group has claimed.

Which? tracked the prices of more than 100 electrical products online over six months at Amazon, Argos, Currys and John Lewis and said it found a number of savings that either did not exist or were much lower than claimed.

The watchdog found Amazon selling a Canon EOS 70D camera with a lens for £967.99 with the claim that it was a saving of £272 off the recommended retail price (RRP) of £1,239.99.

But Which? said Canon's typical price of £959 for the camera meant customers were actually paying £8.99 more.

It found Currys offering a Sony Bravia television for £579 with a claimed saving of £170 from the original price of £749.

But Currys only sold the television at the higher price for three weeks despite running the advertised 'offer' for seven months.

Argos reduced its price for the Nikon D3300 24MP DSLR camera with lens over time but continued to compare the savings to the original cost rather than from the previous month, although it did make clear that the camera had previously been sold at a cheaper price.

Which? found John Lewis lowering the price of its 55JL9000 LED HD Smart TV from the original ticket of £1,699 to £1,599, £1,399 and then £1,299.

At one point Which? said John Lewis was claiming that customers were saving £400 when they were actually saving just £100 compared with the previous week.

Which? said many of the strategies fell within government guidance on special offers because retailers used signs to explain them, but believed many consumers would still be left thinking they were making a bigger saving than they actually were.

A survey by the watchdog found 31% of consumers had bought a product only because it was on special offer, and 41% waited for offers before buying items.

But it said its findings showed that shoppers could be better off seeking out the cheapest price and ignoring the 'offers' altogether.

Which? executive director Richard Lloyd said: 'With many shoppers on the lookout for bargains this Christmas, we've found dodgy discounts that might lure people into buying something they could have found cheaper elsewhere.

'It's time for the Government to force retailers to play fair by setting out new, clearer and tougher rules on special offers.'

Amazon told Which?: 'We work with product manufacturers to provide our customers with a wide range of information about any given product, including RRPs.

'We aim to provide the very latest information.'

A John Lewis spokeswoman said: 'Firstly, it is never our intention to mislead our customers.

'We have thoroughly investigated all of the pricing, online and shop messages for the promotions highlighted. We process a high number of promotions every week and have very robust checking procedures in place. However, our processes do rely on manual input and it appears for one of the examples highlighted there has been an individual human error.'

A Currys spokesman said: 'We are the only retailer to always show customers when and for how long our 'was' prices applied both online and in-store.

'We strictly observe government guidelines on pricing by giving customers clear information.'

• Which surveyed 1,096 members in September.