The FBI warned of concerns over a 'biosecurity risk' from Chinese scientists' research in the US after they intercepted virus samples carried in luggage a year before the coronavirus outbreak.

In November 2018 - just over a year before the first coronavirus case was recorded in Wuhan - US customs at Detroit Metro Airport stopped a Chinese biologist with three samples labeled 'Antibodies' in his luggage.

He told border control that someone he worked with in China had asked him to deliver the vials to a researcher at a US institute.

After examining the writing on the vials, customs agents concluded that they believed the materials inside may have been MERS or SARS materials.

The FBI warned of concerns over a 'biosecurity risk' from Chinese scientists' research in the US after they intercepted virus samples carried in luggage a year before the coronavirus outbreak (file image)

An unclassified FBI report obtained by Yahoo News said: 'Inspection of the writing on the vials and the stated recipient led inspection personnel to believe the materials contained within the vials may be viable Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) materials.'

The report - written by the Chemical and Biological Intelligence Unit of the FBI's Weapons of Mass Destruction Directorate - does not give the name of the Chinese scientist carrying the suspected samples, or the intended recipient in the US.

The WMPP assesses foreign scientific researchers who transport 'undeclared and undocumented' biological materials into the US that 'almost certainly present a biosecurity risk'.

Concerns about China's flouting of biosafety rules is nothing new, but the coronavirus pandemic has exacerbated tensions between Beijing and Washington. Donald Trump has used the phrase 'Chinese virus' in recent weeks

The FBI concluded that the incident, along with two other cases mentioned in the report, were part of an alarming pattern.

It appears to be part of a larger FBI concern about China's involvement with scientific research in the US.

One professor of global biosecurity has said that the FBI appears to be concerned with research that would be used for bioterrorism.

A couple wearing protective suits as a preventive measure against coronavirus walk along a street in Wuhan in China's central Hubei province

They added that the transferring of samples was likely to be going both ways, saying that unless there is a comprehensive surveillance point, nobody knows what people are bringing in and out.

Another expert said that there is a threat posed by Chinese nationals carrying biological samples but that the carrier would likely be someone 'unwitting'.

Concerns about China's flouting of biosafety rules is nothing new, but the coronavirus pandemic has exacerbated tensions between Beijing and Washington.

In recent weeks disagreements have escalated, with President Trump calling COVID-19 'the Chinese Virus,' while Beijing in turn has promoted conspiracy theories claiming the virus originated in a US weapons lab.

In addition, Mike Pompeo added fuel to the fire last week after referring to the disease as the 'Wuhan virus'.