Chinese scientists are responsible for the creation of Covid-19 in a lab in Wuhan, but they tried to reverse-engineer versions of the virus to make it look like it naturally came from bats, claims a new study.

British Professor Angus Dalgleish and Norwegian scientist Dr. Birger Sorensen are authors of the paper. They wrote that they have had "prima facie evidence of retro-engineering in China" for a year.

The allegations in the study obtained by Daily Mail include accusations of "deliberate destruction, concealment or contamination of data" at Chinese labs. It also mentioned the disappearance of scientists in the country who shared their opinion.

In 2020, Dalgleish and Sorensen were studying Covid-19 samples as they were trying to create a vaccine. While doing so they found "unique fingerprints" in the virus that they said could only have emerged from manipulation in a laboratory. They said that they tried to publish it but were ignored by major scientific journals which at the time favored the theory that the virus jumped from bats or other animals to humans.

Now different attempts are being made to find the origins of Covid-19. A few days ago, US President Joe Biden ordered the intelligence community to re-examine how the virus originated. The announcement came after a previously undisclosed intelligence report claimed that several researchers at the Wuhan Institute of Virology were sick and hospitalized in November 2019.

The study by Dalgleish and Sorensen concluded that "SARS-Coronavirus-2 has no credible natural ancestor" and that it is "beyond reasonable doubt" that the virus was made through "laboratory manipulation."

Meanwhile, former Secretary of State Mike Pompeo claimed on Saturday that the Wuhan Institute of Virology was involved in military activity alongside its civilian research, reported Fox News. "What I can say for sure is this - we know that they were engaged in efforts connected to the People's Liberation Army inside of that laboratory, so military activity being performed alongside what they claimed was just good old civilian research," Pompeo said on "Fox & Friends Weekend."

"They refuse to tell us what it was, they refuse to describe the nature of either of those, they refused to allow access to the World Health Organization when it tried to get in there," he added. Pompeo also said that it was important that the Biden administration pursue an investigation into how the pandemic began. "I’ve known since spring of last year, 2020, when I first spoke about this that there is enormous evidence that this escaped from that laboratory in Wuhan," he said.

"We know there were people who got sick there, scientists who got sick there, we know they were doing the gain of function research -- essentially taking viruses and making them more contagious, potentially more lethal, this administration has to get after this," Pompeo added.

Blood samples Blood samples to test for COVID-19 antibodies sit on a table at a clinic in Moscow on May 15, 2020. - Russia registered more than 10,000 new coronavirus infections on May 15, as Moscow unveils mass antibody testing and a national lockdown eases. Photo by VASILY MAXIMOV/AFP via Getty Images