US intelligence agencies are investigating mobile phone data which suggests the Wuhan Institute of Virology had an emergency shutdown back in October last year.
NBC News has reportedly obtained records which show that a "hazardous event" at the institute's high security National Biosafety Laboratory may have occurred between October 6 and 11.
This allegedly led to a shutdown of the P4 laboratory from October 7 to 24, during which there was no mobile activity, news.com.au reports.
The laboratory, located a short distance from the Wuhan wet market at the centre of the coronavirus outbreak, is the facility the Trump administration is blaming for starting the pandemic.
The report, which NBC says was carried out by private investigators, also suggested roadblocks around the laboratory were set up between October 14 and 19.
US spy agencies are reviewing the document, but intelligence analysts examined and could not confirm a similar theory previously, two senior officials told NBC's London-based News Verification Unit.
The report offers no direct evidence of a shutdown, or any proof for the theory that the virus emerged accidentally from the lab.
The outbreak is generally thought to have begun in Wuhan last November.
Both Donald Trump and US Secretary of State Mike Pompeo have favoured a leakage of coronavirus from the laboratory over the prevailing theory that it jumped from bat to humans at a wet market.
Australian Prime Minister Scott Morrison has backed the wet market theory, while calling for an investigation into the outbreak's origin.
Chinese officials have denied a laboratory accident caused the coronavirus outbreak.
US Senator Marco Rubio, who is a member of the US Senate Intelligence Committee, tweeted about the report this week.
He wrote: "Would be interesting if someone analysed commercial telemetry data at & near Wuhan lab from Oct-Dec 2019.
"If it shows dramatic drop-off activity compared to previous 18 months it would be a strong indication of an incident at lab & of when it happened."