US and UK intelligence agencies 'examining report on mobile phone data at Wuhan laboratory'

US and British intelligence agencies are reportedly examining mobile phone data suggesting there could have been an emergency shutdown in October at the Wuhan Institute of Virology.

According to a report, obtained by NBC News, there was no mobile phone activity in a high-security part of the Chinese laboratory complex from Oct 7 to Oct 24. Previously, there had been consistent use of mobile phones.

The report, carried out by private experts, suggested there may have been a "hazardous event," specifically at the institute's National Biosafety Laboratory, between Oct 6 and Oct 11.

Analysis of mobile phone data from the area surrounding the institute also suggested roadblocks were in place between Oct 14 and Oct 19.

Experts urged caution over the report, suggesting it may be based on only limited commercially available mobile phone data, and that there could be other reasons for varying levels of phone usage.

However, the document could be what Donald Trump was referring to when the president recently said he had seen evidence giving him a "high degree of confidence" the pandemic began accidentally at the Wuhan laboratory.

The prevailing theory is that the virus originated in bats and crossed over to humans at a market in Wuhan.

But US intelligence agencies continue to investigate the Wuhan laboratory and Mike Pompeo, the US secretary of state, has said there is a "significant amount of evidence".

It was unclear which private organisation carried out the leaked analysis of the mobile phone location data.

But the 24-page report suggested it "supports the release of Covid-19 at the Wuhan Institute of Virology" and that the pandemic began earlier than previously thought. The first confirmed case so far in China was on Nov 17.

The document was obtained by NBC News in London. In addition to intelligence agencies it has been seen by the US Senate intelligence committee.

Several days ago Marco Rubio, the Republican senator who sits on the committee, wrote on Twitter: "Would be interesting if someone analyzed commercial telemetry data at & near Wuhan lab from Oct-Dec 2019.

"If it shows dramatic drop off in activity compared to previous 18 months it would be a strong indication of an incident at lab & of when it happened."

China has denied that the virus escaped from the Wuhan laboratory.

US officials said they had previously looked at other reports, also based on publicly available mobile phone data, suggesting a shutdown at the Wuhan laboratory.

They went on to examine their own data, including satellite images, and could not establish that there had been a temporary closure at the Wuhan lab, deciding that the suggestion was "inconclusive".