The head of World Health Organization team working with Chinese colleagues to finish a long-awaited report on the origins of the coronavirus acknowledged its authors could face pressures but insisted the final product will have a unanimous green light from all of the team's science-minded members.

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Peter Ben Embarek, an expert on food safety and diseases that jump from animals to humans, said in interviews on Wednesday and Thursday that the team hopes the report now totalling some 280 pages and complete with graphs, dates and annexes will be ready for release next week. The report is a first-phase study that is expected to be followed by a more in-depth look as part of the guidelines set by Chinese officials and the WHO team.

Ben Embarek, who led a 10-person international team of experts that visited China in January and February, acknowledged that political pressures have loomed large over the virus pandemic. We are in the world that we live in, he said. It's possible that there will be pressures from right to left. What we can guarantee is that everyone will be on board and unanimous in their backing of the report once that the text is completed, Ben Embarek said. The fine-tuning of the text has centred on scientific issues, while some Chinese-English translation issues were taking a lot of time, he said. He said the report was being written by all of the experts and part of a long and complex process.

China's Global Times newspaper on Wednesday published an interview with Liang Wannian, the head of the Chinese side of the team, who pointed to political pressures that amounted to huge disrespect to the work of our scientists. Liang was quoted as saying some politicians and international media had "Insisted on politicising the scientific issue of tracing the source of COVID-19, regardless of scientific facts, for their own personal gain, arbitrarily misinterpreting the scientific findings and reports of our joint team".

He took pains to emphasise the spirit of cooperation among the scientists and said both sides had cooperated openly and fully throughout the month-long investigation, and that the results of this joint study in China are the consensus of Chinese and foreign experts. Liang echoed the comments from Ben Embarek about the extended time to publish the report, saying the process required to present a complete and scientifically rigorous report takes some time.

The team did not find cases of COVID-19 before December 8, 2019, he said. Ben Embarek cited the need to investigate the possible role in the pandemic of local trade of wild animal products from farms in and around southern China in 2019 and beyond to a market in the city of Wuhan, which could have been a way that the virus entered into a large city that was tied into global supply chains. We don't know yet the origins of the pandemic. He said cold-chain transmission including through frozen food packaging was a possible route of spread, but that the issue requires further exploration.

Liang promoted Chinese government claims of other sources of the pandemic saying that cold chain transmission plays an important part in the origin and transmission of the epidemic. The international team left open the possibility of the cold chain playing a role in the transmission. It took many months for the U.N. team to arrange a visit to China with Chinese authorities. Critics say the delay cost valuable time in efforts to unearth the origins of a pandemic, which has led to at least 2.6 million reported deaths. China's government detained some doctors who sought to raise the alarm about the outbreak, which is believed to have originated in or near Wuhan in late 2019.

WHO repeatedly praised the Chinese government's early response, even though recordings of private meetings obtained by The Associated Press exposed how top officials at the UN health agency were frustrated at China's lack of cooperation.