Wearing a face mask is not encouraging people to stop social distancing, as some had feared, researchers said on Friday, two weeks since masks were made compulsory in busy parts of Amsterdam and Rotterdam.

Researchers from the VU university institute NSCR, which focuses on crime and law enforcement, studied camera footage from an average Amsterdam shopping street in May and June – before the ban was introduced. They found people who voluntarily wore a mask were just as likely to ignore social distancing rules as those without.’

‘We can cautiously say that we don’t need to worry that face masks will give people a false sense of security and reduce social distancing,’ lead researcher Marie Rosenkrantz Lindegaard told the Volkskrant.

The researchers found 55% of people walking down the street broke the 1.5 metre rule, and 12% passed within 50 centimetres of someone else. There was no difference between mask wearers and those without.

‘We think the crucial factor is how busy the street is,’ Lindegaard said. ‘That means if you want to enforce social distancing, you have to do more in terms of crowd management. Make sure too many people don’t come to the same place at the same time and ensure clear separate streams of movement.’

Amsterdam and Rotterdam made face masks compulsory in some markets and busy shopping streets earlier this month, but the rule is being widely flouted, particularly in Amsterdam’s red light district.

On Thursday it emerged that just 20% of visitors to Amsterdam’s red light district are wearing a mask, although that does go up to 80% when street wardens intervene.

Amsterdam and Rotterdam were given the go ahead to introduce masks as an experiment to see what impact they have on social distancing. Ministers and government experts have maintained that masks may give people a false sense of security about the risks.

Lindegaard also found that one in five people who wore a mask voluntarily were not wearing it properly, with 8% leaving their noses uncovered.

She and her team are now analysing the results of camera footage in places where masks are compulsory. Shopkeepers on Thursday sounded the alarm, saying their turnover has gone down by some 40% since the requirement was introduced.