NEW DELHI: A laboratory leak was the most likely origin of the Covid-19 pandemic that wreaked havoc across the world, the Wall Street Journal (WSJ) has reported, citing findings by the US Energy Department.According to a classified intelligence report provided to the White House and key members of Congress, the deadly virus likely spread due to a mishap at a Chinese laboratory.The American Energy Department had previously been undecided on the source of the virus.

The conclusion is due to new intelligence, but the department made its judgment with “low confidence,” according to people who have read the classified report, the WSJ said.The report also highlighted how other agencies judged that the spread of the virus was likely the result of a natural transmission, while others are undecided."The updated document underscores how intelligence officials are still putting together the pieces on how Covid-19 emerged.

More than one million Americans have died in the pandemic that began more than three years ago," the report said.The report, however, reaffirmed an existing consensus between that Covid-19 wasn’t the result of a Chinese biological-weapons programme, sources told WSJ.Lab leak theory vs natural origin theoryThe origin of Covid-19 is still the subject of ongoing scientific investigation and debate.

While the exact origin is not yet fully understood, the scientific consensus is that SARS-CoV-2 most likely originated in animals, with bats being the leading suspect, before it jumped to humans, possibly through an intermediate host.However, the theory that the virus may have accidentally leaked from a laboratory, specifically the Wuhan Institute of Virology (WIV) in Wuhan, China, has also been a subject of debate and investigation.In 2021, US President Joe Biden had ordered intelligence officials to "redouble" efforts to investigate the origins of Covid-19, including the theory that it may have originated in a laboratory in China.Earlier this month, the World Health Organization (WHO) said it will continue pushing until it finds an answer to how the Covid-19 pandemic started.Solving the mystery of where the SARS CoV-2 virus came from and how it began spreading among humans is considered vital for averting future pandemics.The WHO carried out a first phase of investigation by sending a team of international experts to Wuhan, China, in early 2021 to produce a first phase report, written in conjunction with their Chinese counterparts.But that investigation faced criticism for lacking transparency and access, and for not sufficiently evaluating the lab-leak theory, which it deemed "extremely unlikely".The political rhetoric reached fever-pitch over that theory, which was favoured by the administration of former US president Donald Trump but always flatly rejected by China.Overall, while the origin of Covid-19 remains uncertain, the available evidence suggests that it likely originated in animals and was transmitted to humans.Some scientists argue that the virus probably emerged naturally and leapt from an animal to a human.Yet no confirmed animal source for Covid-19 has been identified yet.

"The lack of an animal source, and the fact that Wuhan is the center of China’s extensive coronavirus research, has led some scientists and US officials to argue that a lab leak is the best explanation for the pandemic’s beginning," the WSJ report said.According to the report, Wuhan is home to an array of laboratories, many of which were built or expanded as a result of China’s traumatic experience with the initial severe acute respiratory syndrome, or SARS, epidemic of 2002.

Moreover, the fact that some Wuhan scientists reportedly fell ill with symptoms similar to Covid-19 prior to the outbreak of the pandemic has been used by some, including US intelligence, as evidence to support the theory that the virus may have originated in a laboratory.

However, a US House Intelligence Committee report concluded last year that this disclosure didn’t strengthen either the lab-leak or the natural-origin theory as the researchers might have become sick with a "seasonal flu".