The U.S.-led "Five Eyes" intelligence alliance said on Tuesday that tech firms must allow law enforcement agencies access to encrypted material, warning that failing to do so put people at risk.

After a two-day summit in London, senior ministers from the group comprising the United States and allies Britain, Canada, Australia and New Zealand, said encryption should not come at the expense of the public's safety.

"We are concerned where companies deliberately design their systems in a way that precludes any form of access to content, even in cases of the most serious crimes," the group said in a statement following the conference.