Extra coronavirus testing will be carried out in areas of south London after a case of the South African variant was discovered.

The surge testing and genomic sequencing will be rolled out in parts of West Norwood and a small section of Streatham in the borough of Lambeth, the Department of Health and Social Care said.

People over the age of 16 living or working within the SE27 0, SE27 9 and SW16 2 postcodes are strongly encouraged to take a Covid-19 test this week, whether they are showing symptoms or not.

Lambeth council said: “This is to help us track any potential cases after a case of the variant of Covid-19 that was first identified in South Africa was discovered in the area.”

Free testing kits will be delivered to people’s doorsteps and collected by a team of volunteers, who will not need to enter the household, the council said.

Those who are not going to be at home can book an appointment at a mobile testing unit at Leigham Court Road car park, in Streatham Wells, or Waylett Place car park, in Norwood.

People with symptoms should book a test in the usual way while others should visit their council website.

It comes as Home Secretary Priti Patel is looking into the case of a passenger arriving in the UK from South Africa without receiving any checks.

Door-to-door and mobile testing began at the start of the month after 11 cases of the variant were identified in people who had no links to travel – suggesting it may be spreading in communities.

Dr Susan Hopkins, from Public Health England, told a briefing for journalists on Tuesday that 170 cases of the South African variant had been identified so far, including 18 that are not linked to travel.

Surge testing began in Worcestershire on Saturday in the WR3 postcode after cases of the variant with no links to international travel were identified.

Testing of people in Maidstone, Kent, and Woking, Surrey, is now complete.