Requests by UK experts to Chinese authorities for samples of the latest strain of a dangerous and evolving avian influenza virus, known as H7N9 have so far been ignored, the Telegraph has learned.

The news comes on the back of revelations earlier this week by the United States’ government that China has, for over a year, refused its requests to share lab samples of the same strain of avian influenza virus.

To date there have been 1,625 cases of H7N9 – a virus which usually circulates in poultry – in humans including a spike in cases in 2017, which prompted US researchers to request samples of the virus from Chinese authorities.

The virus is thought to be only few mutations away from being able to spread freely in humans and was said by the England's deputy chief medical officer, Jonathan Van Tan, earlier this year to be a likely candidate for the next global flu pandemic.

Under World Health Organization (WHO) rules, countries are required to share flu viruses that have the potential to cause pandemics to help other nations prepare in the case of a global outbreak.

The sharing of viruses comes under the remit of various government agencies with health considerations sometimes pitted against competing interests such as concerns over bio-security and commercial interests in developing treatments.