Judges look likely to continue using their powers of name suppression despite the risk that they will be undermined by the Internet.

The case of the billionaire drug-smuggler has highlighted how easily the Internet can destroy a judge's decision to prevent the public knowing the identity of an offender.

But in their ruling released on Tuesday, Justices Nicholson and Potter said they did not quash the order suppressing the billionaire's name simply because it appeared on the Internet.

They pointed out that the reason the order did not work was because somebody sitting in court on January 6 or 7 leaked the name.

The billionaire, still known here only as L, was granted permanent name suppression when he appeared in the Otahuhu District Court for importing cannabis.

But within hours, his name and full details of his court appearance and background had been posted on the Internet by overseas media outlets.

This case is not the first where suppressed names have turned up on screens around the world.

The Internet got the better of Britain's Security Intelligence Service when former spy Richard Tomlinson threatened to publish names of MI6 spies on his Web page. The threat backfired when the kind of list he had been talking about, naming 160 MI6 spies, hit cyberspace.

When the British Government banned Mr Tomlinson's Web page, sympathisers "mirrored" it all over the Internet.

Mr Tomlinson said: "This shows the freedom of speech provided by the Internet is far more powerful than the outdated secrecy laws of a minor state."

John Burrows, professor of Law at Canterbury University, said the Internet made no difference to name suppression laws. The trouble would always be tracking down the source of the leak.

"The principle [of name suppression] is still the same. Once a court has made an order, nobody can publish the name outside the court.

"At the very least it does stop publication in New Zealand and if the person who has published it is discovered, of course the penalties can be quite severe."

However, Jim Tully, head of journalism at Canterbury University, said the Internet had made it necessary for the justice system to reconsider suppression.

"Any law has got to be workable and sensible. If technology has changed the context in which something like suppression operates, then maybe the courts should be asking how realistic the orders are."