MOBILE phones in schools should be banned because they pose a much graver risk to children's education than previously considered, the author of a flagship report on their use says.

Increasing phone ownership is causing unprecedented classroom distractions, academic Richard Murphy said. An outright ban on their use in schools is needed more than ever, said Murphy, a professor at the University of Texas at Austin.

Murphy previously co-authored a study that claimed banning phones from schools gives pupils an extra week's education during an academic year.

The findings looked at schools in four English cities and found test scores increased by more than six per cent in those which banned phones from 2000 to 2012.

However, Murphy said the disruption to children's eduction was now much more severe due to an increase in phone ownership.

Speaking to the Sunday Herald, Murphy said lower achieving students were more likely to suffer the harmful effects of phones in schools.

Murphy said: “It seems the unstructured presence of multipurpose technology in the classroom damages academic performance."

He added: "Our paper was looking at the introduction of phone bans between 2000 and 2012, when mobile phone ownership was less prevalent.

“I would imagine that the negative impact of phones that we find on previously low achieving students would be greater now with more students owning phones.”

Murphy said the type of ban brought in needed to be thought through.

He added: “Schools need to think of policies that would be the most effective whilst keeping the disruption they cause to a minimum. Teachers spending all their time getting students to turn of their phones does not sound like an optimal policy.”

In France, mobile phones are under a complete ban in schools. Pupils leave their phones in named boxes or bags at the school entrance in the morning and retrieve them as they leave for home.

Murphy co-authored the original report with Louis-Philippe Beland, an assistant professor of economics at the Louisiana State University.

The research published by the London School of Economics, surveyed the test scores of secondary schools in Birmingham, Leicester, London and Manchester before and after test bans on phones were introduced.

In 2015, New York mayor Bill De Blasio lifted a 10-year ban on phones on school premises saying it would reduce inequality.

However, Murphy and Beland disputed the politician's claims.

"The results suggest that low achieving students are more likely to be distracted by the presence of mobile phones while high achievers can focus in the classroom regardless of the mobile phone policy," their study said.

"Schools could significantly reduce the education gap by prohibiting mobile phone use, and so by allowing phones, New York may unintentionally increase the inequalities of outcomes," it added.