Rising numbers of people testing positive for Covid-19 are refusing to hand over details of close contacts, as the numbers forced to self-isolate reached a record high.

Official statistics show almost one quarter of people who tested positive for Covid-19 in the week ending July 21 would not provide details of any recent close contacts.

In total, 76.9 per cent of such cases provided such details – with compliance falling by almost 10 per cent in the last month.

Latest weekly figures for England show almost 1.3 million isolation orders sent out by app or NHS Test and Trace, the highest on record.

The figures show 678,102 people pinged by the app in the week ending July 21, up 11 per cent from the previous week. It is the third consecutive week that more than half a million people have been told to self-isolate by the app.

Separate figures show 597,260 people were identified as close contacts of a positive case by NHS Test and Trace, a 25 per cent jump in one week.

The statistics show that in total, 307,758 people tested positive for coronavirus, an 18 per cent rise in a week, and the highest number since mid January.

The report also suggests that those contacted by call handlers may be increasingly reluctant to respond to calls, or to hand over details of their contacts.

The proportion of people who tested positive for Covid-19 but who were not reached by the system rose to 14.8 per cent, the highest proportion since October 2020. The category covers those who do not respond to efforts by NHS Test and Trace to contact them.