England's Covid-19 mobile phone app will be tweaked so that fewer contacts of asymptomatic people who test positive for the disease will need to self-isolate, Britain's health ministry has said.

Under the change, if someone tests positive but is asymptomatic, the app will look for their close contacts in the two days prior to the positive test, rather than looking for the contacts of the positive person in the five days before the test, according to a Reuters report.

The health ministry said that the change would reduce the number of notifications sent by the app, but would not reduce the app's sensitivity, and it would still catch the same number of high-risk contacts.

“We want to reduce the disruption that self-isolation can cause for people and businesses while ensuring we're protecting those most at risk from this virus,” health minister Sajid Javid said.