London, Jul 13 (IANS): Parents, take note. If you think that Internet filtering tools -- such as parental controls -- will stop your teenage child from accessing explicit sexual content online then you may be wrong, a new study suggests.

The findings, published in the journal Cyberpsychology, Behaviour and Social Networking, indicated that Internet filtering tools are ineffective.

According to the researchers from the University of Oxford in Britain, the use of Internet filtering tools is widespread but there has been no conclusive evidence on their effectiveness until now.

"It's important to consider the efficacy of Internet filtering. Internet filtering tools are expensive to develop and maintain, and can easily 'underblock' due to the constant development of new ways of sharing content," said co-author Victoria Nash.

The research team presented two studies -- one exploratory analysis of secondary data collected in the European Union and one preregistered study focused on British adolescents and caregivers -- with nearly 15,000 participants.

"We were also interested to find out how many households would need to use filtering technologies in order to stop one adolescent from seeing online pornography," said co-author Andrew Przybylski.

"The findings from our preliminary study indicated that somewhere between 17 and 77 households would need to use Internet filtering tools in order to prevent a single young person from accessing sexual content," Przybylski added.

The results from follow-up study showed no statistically or practically significant protective effects for filtering.

The researchers noted that there should be more research done to solidify these findings.