Powys scientist Professor Neil Ferguson has suggested Britain should follow South Korea's model of easing the lockdown.

Professor Ferguson, who studied in Llanidloes and is now a key figure in informing the Government's coronavirus response from his role with Imperial College, was the lead author of a report which warned 250,000 people could die during the Covid-19 pandemic if the Government did not introduce social distancing.

Now he has told news website UnHerd that the UK will have to "substitute other measures" in order to move away from the current lockdown.

He said South Korea – which has implemented a successful programme of mass testing and contact tracing – has been "remarkably effective" at tracking transmission.

The country has one of the lowest Covid-19 case mortality rates worldwide, with 240 reported deaths.

But he warned that an alternative strategy of shielding could be expected to lead to as many as 100,000 deaths in the UK later this year.

"I think the country we should be looking at though is South Korea, which is a much better model and has a way lower mortality rate per capita than any of the countries we've been discussing so far," he told the website.

"I think if you talk to people in Korea, and people in the public health department, they think they have a sustainable strategy.

"They have society, not operating as normal, there will have to be social distancing until we have a vaccine, it won't be normal society but they have been remarkably effective at basically tracking chains of transmission down and isolating people who are infected.

"And the real benefit of those policies is that if you drive transmission down to the very low levels they now have in Korea, then it's not that disruptive or resource-intensive.

"You only have a few hundred cases a week, yes that results in a few thousand people a week requiring isolation, but it's very different from having a harsh chunk of your population in isolation."

Through a process of mass testing and isolating infected people and their contacts, ministers hope that future localised outbreaks of coronavirus can be kept under control.

Health Secretary Matt Hancock has said that cases need to drop substantially before this next phase can be truly effective.

Prof Ferguson said that a model on easing lockdown measures by his team was in progress, and expected to be released in the coming days.

He told UnHerd that shielding scenarios were being modelled, but said he was sceptical it would be a "viable strategy".

"We are modelling exactly those scenarios and it is, in practical terms, you would require a very high level of effective shielding for that to be a viable strategy," he said.

"The most vulnerable people are also the people who most need care and have most interaction with the health system and are least able to really be truly isolated.

"I'm very sceptical we can get to the level of shielding which would make that a viable strategy.

"In theory, it might be, but until I see a country or even a community do a better job than we've seen so far, then I remain sceptical that it's achievable.

"And if you achieve just 80 per cent shielding, 80 per cent reduction in infection risk in those groups, we'd still project you get well over 100,000 deaths later this year through that sort of strategy."