COVID-19 most likely leaked from a lab in Wuhan, the US Energy Department has concluded.

The Wall Street Journal reports that the department came to the conclusion in a classified intelligence report recently provided to the White House and key members of Congress.

It marks a change in the department’s position on how the virus emerged.

Previously is has said it was "undecided" on how COVID came about.

The department said it had come to its conclusion with ‘low confidence’.

The FBI also believes a lab leak is the most likely source; however, it has reached the conclusion with “moderate confidence”.

Four other US agencies, as well as a US national intelligence panel, say they believe the virus was likely the result of natural transmission.

Two agencies remain undecided.

The US Energy Department’s conclusion is viewed as significant because it oversees a network of US national laboratories, some of which conduct advanced biological research.

Around the world, conflicting theories remain over whether the virus emerged naturally or came out of the Wuhan Institute of Virology.

In Ireland, 1.7 million COVID cases have been reported since the outbreak of the pandemic.

Some 8,655 deaths have been linked to the virus.