A man who claimed to have seen Dominic Cummings in Durham for a second time in April has admitted that he made it up, according to reports.
Tim Matthews said he altered figures on the popular Strava running app to make it look like he had seen Mr Cummings in Durham on April 19, after the PM's aide had returned to London from his first trip.
His claim was reported in the Guardian earlier this week.
But he told the Mail on Sunday: "I made that up afterwards, a few days ago in fact. I modified it for a little bit of comedy value.
"I undid it later, I’m sorry. A bit of comedy value even if it was really inappropriate."
He added: "The only thing that I can definitively say is that at some point during the last few months when I was out running, I had occasion to think to myself, 'That’s Dominic Cummings'.
"What I can’t tell you is any sort of timeframe other than in the last few months."
Mr Matthews is one of two people who originally claimed to have seen Mr Cummings on April 19.
The Government adviser is reported to have remarked "Aren't the bluebells lovely?" to passersby.
Mr Cummings and the Government have repeatedly denied reports of a second trip to Durham.
Calls for Mr Cummings to be sacked have come from across the political spectrum since it emerged that the adviser made the 250-mile trip to his parents' estate in Durham during the lockdown with suspected coronavirus, as well as later driving to local beauty spot Barnard Castle.
Mr Cummings said he drove to Durham to secure childcare for his son, 4, while he explained the 30-mile trip to Barnard Castle as a chance to test his eyesight before driving back to London.
Boris Johnson and other cabinet members have stood by Mr Cummings, saying he acted reasonably.
A Durham police investigation this week found that Mr Cummings might have committed a minor breach of lockdown rules.