TENS of thousands of Irish households who own illegal 'decoding' boxes have had their free access to cable TV finally turned off for good.

Cable provider Chorus NTL last week confirmed that new security arrangements put in place in January have been a complete success – rendering the so-called 'dodgy boxes' redundant.

Around 100,000 of the devices – which illegally decode pay-TV stations – were purchased by Irish customers in 2008 alone, according to a survey of suppliers earlier this year.

While an exact figure is difficult to ascertain, the use of the devices was costing both cable providers and television companies millions of euro in lost revenue every year – certainly enough to justify the funding of anti-piracy operations.

It has also been estimated that one in five cable television subscribers had purchased the dodgy boxes meaning that some 20% of the market was availing of pay-TV stations – at no extra cost.

The decoders work by decrypting digital signals sent through the cable network and are generally purchased online or at markets. They can purchased for around €150.

In January, a basic domestic digital subscription package cost around €240 a year compared to €880 for all channels, giving an indication of the levels of income which were being lost to the black market.

Previous attempts to thwart the effectiveness of the boxes proved temporarily successful but new signal encryptions were eventually 'hacked'.

However, a spokeswoman for UPC, the parent company of Chorus NTL whose service was pirated, said it hoped the new measures would now mean a complete end to the scam.

"This is part of a counter measure that we had said to the market we would deploy from 2009," she said. "We have a dedicated anti-piracy team that is in place and they are constantly monitoring the situation."

As part of the roll-out of layered security measures, NTL customers are also being issued with new decoder cards.

"We have been telling people 'don't buy them' because you are going to be buying boxes that are going to be redundant," the spokeswoman said.

She added that the new measures are likely to spell the end for the illegal practice.

"That would be our hope and certainly all the signals would say that.

"But it's a battle that we will be constantly monitoring and that is why we have a piracy team in place," she said.