Amid calls for a fresh probe into the origins of COVID-19, an explosive new study has found that Chinese scientists created the virus in a lab in Wuhan, then tried to cover their tracks by reverse-engineering versions of the virus to make it look like it evolved naturally from bats.

The novel coronavirus SARS-CoV-2 virus has no "credible natural ancestor" and was created by Chinese scientists who were working on a "Gain of Function" project in a Wuhan lab, the Daily Mail reported on Sunday, citing a new research paper by British professor Angus Dalgleish and Norwegian scientist Dr Birger Sorensen.

The new research claims that scientists took a natural coronavirus "backbone" found in Chinese cave bats and spliced onto it a new "spike", turning it into the deadly and highly transmissible COVID-19.

The paper also quotes that researchers found "unique fingerprints" in COVID-19 samples that they say could only have arisen from manipulation in a laboratory.

Authors Dalgleish and Sorensen wrote in their paper that they had prima facie evidence of retro-engineering in China'' for a year, but were ignored by academics and major journals, reported DailyMail.com.

The study alleged "deliberate destruction, concealment or contamination of data" at Chinese labs and notes the silencing and disappearance of scientists in China who spoke out about the activities.

The research, has been obtained by DailyMail.com, is expected to intensify the ongoing debate on China's role in creating the virus that has claimed thousands of lives.

In the 22-page paper which is set to be published in the scientific journal Quarterly Review of Biophysics Discovery, Dalgleish and Sorensen pieced together how Chinese scientists, some working with American universities, allegedly built the tools to create the coronavirus.

Incidentally, "Gain of Function" projects, which involves tweaking natural viruses to make them more infectious, had been outlawed by former US President Barack Obama.

In an exclusive interview with DailyMail.com, Sorensen said that four amino acids on the spike have a positive charge, which causes the virus to tightly cling to the negatively charged parts of a human, becoming more infectious.

Because these positively charged amino acids also repeal each other, it was rare to find even three in a row in naturally occurring organisms, while four in a row is ''extremely unlikely, he said.

"The laws of physics mean that you cannot have four positively charged amino acids in a row. The only way you can get this is if you artificially manufacture it," Dalgleish told DailyMail.com.

"The implication of our historical reconstruction, we posit now beyond reasonable doubt, of the purposively manipulated chimeric virus SARS-CoV-2 makes it imperative to reconsider what types of Gain of Function experiments it is morally acceptable to undertake," they wrote.

In the paper, the scientists wrote that a natural virus pandemic would be expected to mutate gradually and become infectious but less pathogenic, which did not happen in the case of Covid-19.

Dalgleish and Sorensen claimed that after the pandemic began, Chinese scientists took samples of the COVID-19 virus and "retro-engineered" it, making it appear as if it had evolved naturally.

"We think that there have been retro-engineered viruses created. They've changed the virus, then tried to make out it was in a sequence years ago," Dalgleish told DailyMail.com.

The scientists also highlighted that Chinese scientists who wished to share their knowledge have not been able to do so or have disappeared.

Sorensen said that he believes the virus escaped from lower security areas of the institute, where he believes Gain of Function research was performed, reported DailyMail.com.

"We have seen lab leaks and we know it''s happening. We also know from the reports we''ve seen, that coronavirus is worked on in Biosafety Level 2 or 3 labs. If they do Gain of Function in such labs, what do you expect?" he said.

In February 2020, Botao Xiao, a molecular biomechanics researcher at South China University of Technology, published a paper claiming "the killer coronavirus probably originated from a laboratory in Wuhan," highlighting safety issues at the institute. However, he withdrew the paper weeks later after Chinese authorities denied any accidents at the lab.

Dalgleish further told DailyMail.com that he believed China's resistance to the theory that COVID-19 is a man-made, escaped virus comes from scientists fearful that the revelation would shut down their field.

"This looks like a weak defence to protect the discipline so that this type of genetic engineering will not be interfered with. I make no bones about it. The Gain of Function engineering should have been banned ages ago," he said.

Despite former MI6 chief Sir Richard Dearlove saying publicly that the scientists'' theory should be investigated, they said their research was dismissed by major scientific journals that were adamant that the virus jumped naturally from bats, reported DailyMail.com.

However, leading academics, politicians and the media have now begun to contemplate the possibility that Covid-19 escaped from the Wuhan Institute of Virology (WIV) in China - where experiments included manipulating viruses to increase their infectiousness in order to study their potential effects on humans.

Meanwhile, US President Joe Biden on May 26 said he has asked the US intelligence community to "redouble their efforts" to come to a conclusion on the origins of Covid-19 and report back to him within 90 days.

China state media rejected the idea that COVID-19 had originated there and said that it is "a conspiracy created by US intelligence agencies"

A few days ago, an article was published in the Wall Street Journal which revealed that three researchers at Wuhan Institute fell ill in November 2019 and had to be hospitalized. The report was based on previously undisclosed US intelligence. The researchers were admitted into the hospital a month before China reported the first case of COVID-19.

The revelation has sparked debate and raised questions about whether China knew of the deadly virus way before it apprised the world.

Recently, former New York Times science journalist Nicholas Wade published an article in the Bulletin of the Atomic Scientists where he argues that evidence is stronger than the virus leaked from a lab than that it occurred naturally.

In an elaborate report, Wade said that much of the work of Chinese virologists on gain-of-function in coronaviruses was performed at the BSL2 safety level lab, which requires taking fairly minimal safety precautions. The pandemic broke out in the Chinese city of Wuhan in December 2019."For the lab escape scenario, a Wuhan origin for the virus is a no-brainer.

Before that, an Australian daily revealed that Chinese scientists were thinking about bioweapons, visualising a World War-III scenario. The Weekend Australian newspaper cited a Chinese government document that discussed the weaponisation of SARS coronavirus.

DailyMail.com further reported that China had installed the first of a planned five to seven Biolabs in Wuhan in 2017 for the purpose of studying the most high-risk pathogens, including the Ebola and the SARS viruses.

In March, World Health Organization (WHO) Director-General Tedros Ghebreyesus also called for further studies after the release of an inconclusive report on an international team's field visit to Wuhan to research the origins of Covid-19, citing difficulties accessing raw data.