UK Prime Minister Boris Johnson has admitted he does not know how many contacts of Coronavirus cases have been missed.
Johnson has blamed a spreadsheet blunder for nearly 16,000 missing positive test results, reports the Independent.
The prime minister said "some of the data got truncated and it was lost", when asked how the damaging mistakes had been made.
And, asked about the scale of the contacts that had been missed, he said: "I can't give you those figures.
"What I can say is all those people are obviously being contacted and the key thing is that everybody, whether in this group or generally, should self-isolate."