A survey of over 12,000 goods on sale through the Argos catalogue has found that customers in the Republic pay more than Northern Ireland customers for a staggering 99pc of items.

The study was carried out by a professor of Computer Sciences at University College Dublin using a computer programme he had devised to compare Ikea prices.

Prof Barry Smyth admitted he was surprised that the price difference between Ikea in Belfast and Dublin was "only" 8pc on average, as he had expected customers in the so-called "rip-off Republic" to be paying even more.

However, he was surprised in a different way when he discovered that southern customers are paying an average of 24pc more than those up north when shopping at Argos.

"These averages disguise a multitude of savings, and there are literally hundreds of products that are 40pc to 200pc more expensive in Irish Argos stores compared to UK stores," Prof Smyth said.

He said that a three-in-one canopy for babies in prams, for example, costs less than €12 in Belfast. The same product in Dublin costs €35.99, a mark-up of more than 220pc.

But it is on the 'big ticket' items that cash savings are most pronounced.

"If you are interested in a flat screen TV then Argos will charge you, on average, an extra €400 for the privilege of shopping in the Republic," Prof Smyth said.

"In fact, the biggest price difference that I have found so far is €1,124, which you pocket by purchasing a 52 inch high-definition Sony LCD TV up north. This product is listed as €3,339.99 on the Irish site but comes in at only €2,213 (£1,899.99) on the UK site."

Prof Smyth said he found almost 500 products -- mainly in consumer electronics, furniture and leisure equipment -- which are at least €100 cheaper in Argos Belfast than Argos in the south.

When studying Ikea, Prof Smyth admitted that the 8pc price difference could largely be explained by the difference between our 21.5pc VAT rate and the 15pc rate in the North.

However, he said that Argos could not fall back on the same excuse.

"Even after adjusting for this [by calculating the price before VAT is applied] the average Irish product is still 17pc more expensive than its UK equivalent," he said.

An Argos representative was unavailable for commment.