A poll conducted by security firm Sophos has revealed strong objections to hacking into the computers of suspected child abusers.

The poll was prompted by the sentencing of 66 year-old former judge Ronald C Kline on evidence obtained by hackers.

Canadian hacker Brad Willman installed a Trojan in a file claiming to contain child pornography and then broke into PCs looking for evidence.

The survey found that 64 per cent of respondents thought that it was not suitable to hack a computer, even if there was a suspicion that the owner was involved in child abuse.

"Not only is vigilante hacking illegal, it can seriously compromise a police investigation. For instance, a suspect could argue that the hacker had planted the illegal material on their PC," said Graham Cluley, senior technology consultant at Sophos.

"Authorities investigating potential suspects may even fall victim to cyber-attacks themselves as they download evidence from sites such as the one targeted by Willman."

Kline was sentenced to 27 months after being convicted.