2. Tracking mid of jungle near Danaoshan, a village with the closest known relative of COVID19.
3. Tracking from car window
4. Tracking of police tail
5. Mid of driver's phone as police call UPSOUND (Dai dialect) Police: "Don't tell them we're calling."
6. Various of village roadblock
SOUNDBITE (Mandarin) Villager: "No, we do not have bats here."
7. Various aerials
Mengla, Yunnan, China – 2 December 2020
8. Wide of sunset
9. Tilt down from jungle to cave entrance
10. Various of cave interior
Stinson Beach, California – 20 November 2020
11. SOUNDBITE (English) Jonna Mazet, Professor of Epidemiology and Disease Ecology at UC Davis:
"If we want to keep this from happening again, we have to understand this virus-host-environment relationship and what we are doing to put ourselves at risk so that we can take steps to prevent these things from happening again."
More than a year since the first known person was infected with the coronavirus - with at least 1.7 million people killed by it worldwide since - an AP investigation shows the Chinese government is strictly controlling all research into virus origins while promoting fringe theories the pandemic originated elsewhere.
Scientists are searching for the origins of COVID-19 in caves around the world from Thailand to Brazil.
The virus that causes COVID-19 likely originated in a bat, and either leapt to humans directly from a bat or via another mammal.
Over the hills of Mojiang in Yunnan province, China, scientists found the closest known relative of COVID-19 virus.
It is a key location in the search for the source of the pandemic.
But for scientists and journalists, the area is now a forbidden zone – an area of intense sensitivity and secrecy.
Researchers have been stopped by police who confiscated their samples and coronavirus specialists have been ordered not to speak to the press.
AP journalists who visited in late November were tailed by a police and blocked by villagers.
Police called the team's drivers, and said: "Don't tell them we're calling."
Villagers set up a roadblock and said, "No outsiders are allowed in." They claimed to know nothing about bats and coronaviruses. "No, we do not have bats here."
But an AP investigation has found that while China is hampering outside scrutiny into the origins of the virus.
There is quiet government support for select teams searching for the origins.
In one cave in Yunnan province visited recently by the AP, bats flittered out of the cave and flew over a nearby village.
Villagers said until recently, the cave was used as a sacred place by a Buddhist monk from Thailand.
Contact like this between bats and people, praying in caves, hunting or mining, gives new viruses the chance to jump between species.
"If we want to keep this from happening again, we have to understand this virus-host-environment relationship and what we are doing to put ourselves at risk so that we can take steps to prevent these things from happening again," said Jonna Mazet, Professor of Epidemiology and Disease Ecology at UC Davis.