Germany’s foreign intelligence service believed there was a 80-90% chance that coronavirus accidentally leaked from a Chinese lab, German media say. Two German newspapers say they have uncovered details of an assessment carried out by spy agency BND in 2020 but never published.

The intelligence service had indications that the Wuhan Institute of Virology had been carrying out experiments where viruses are modified to become more transmissible to humans for research, they say.

China repeated its denial saying the cause “should be determined by scientists” - and pointed to a World Health Organization investigation which found the lab-leak theory was “extremely unlikely”.

The lab leak hypothesis has been hotly contested by scientists, including many who say there is no definitive evidence to back it up. But the once controversial theory has been gaining ground among some intelligence agencies - and the BND is the latest to entertain the theory. In January, the US CIA said the coronavirus was “more likely” to have leaked from a lab than to have come from animals.