Websites will have to be extra careful to protect children from sexual predators to avoid legal action from a new government agency.

The Child Exploitation and Protection Centre (CEOP) was set up this year to allow the public to easily contact authorities and companies involved in the internet and communications industry. One of the aims of CEOP is to make it easier for people to report when children are unsafe online.

Jim Gamble, the former anti-terrorist police officer who leads the agency, said that legal action would be considered against sites that are "obstructive or unhelpful", and that such sites would be "named and shamed".

"You need to look at those sections of the internet that create a risk, then you have to think about inhibiting people from going to them," Mr Gamble told the Financial Times.

Microsoft, working with CEOP, has already added a "report abuse" button to its MSN Messenger software, which will put children in touch with CEOP and the police to report suspected sexual predators using the service.