Seven in 10 parents snoop on their children's online activities, a study by a search engine has found.

Yasni said that more than half of the parents (56 per cent) who took part in its survey were particularly worried about the information their kids were putting on social networking sites.

They were concerned that publicly available contact details, such as names and addresses, left their children vulnerable to identity theft. One in ten was concerned that their children may meet people whom they considered 'undesirable'.

The company, which enables people to search for others by typing a name into its search facility, said others wanted to know what was being written to ensure their child was not a victim of the growing trend of cyber bullying.

Steffen Ruehl, CEO and co-founder of Yasni, said the site offers an email alert system through which users can receive a regular automated update for a name of their choice. Parents can choose their child's name to keep an eye on what they are saying online.

"There is no doubt that there is a huge increase in parents monitoring their children's online activity in the UK as parents become increasingly wary of the information their kids are putting on the web.

"Our site can help parents to quickly and efficiently monitor what their kids are saying online and, where necessary, take action to prevent anything untoward happening via the internet."