These circumstances – along with fears of an all-out epidemic – had made the spread and consumption of misinformation more likely, experts said.

Masato Kajimoto, a journalism professor at the University of Hong Kong who studies misinformation, said in an era of fake news, truth and accuracy could take second place to eyebrow-raising rumours.

“If you look at the claims and content that go viral quickly, they're often very emotional and match pre-existing beliefs,” he said.

Here are some of the claims made so far and how they have been challenged: 

CLAIM

On February 5, rumours circulating on WhatsApp claimed the city’s supermarkets faced shortages of essential goods, from toilet paper to vegetables, as mainland suppliers reportedly stopped production. Several media outlets including the Post reported long queues and empty shelves across supermarkets in recent days.

RESPONSE

Two of Hong Kong’s largest supermarket chains came out to dismiss the production claims.

Wellcome, which has more than 240 stores across the city, rejected the rumours on Wednesday and said it was “working closely” with suppliers to ensure its stores were well-stocked.

ParknShop acknowledged that day a surge in demand for its products, but reassured customers there would be a wide range of stock available as manufacturers returned from the Lunar New Year holiday.

The Hong Kong government said on Wednesday there was no need for the public to worry, condemning those who spread false claims with “evil intentions”.

It added that recent cross-border restrictions at checkpoints did not apply to goods delivery and that all supplies including rice and noodles were running normally.

CLAIM

Images online claimed that mainland Chinese citizens, refused accommodation from hotels, were living in tents in the city’s North Point district.

RESPONSE

The government said in a Facebook post on Sunday the tents were actually occupied by domestic helpers gathering on their day off.

That followed a January 28 Facebook post by Cheng Tat-hung, a pro-democracy member for the Eastern District Council, who had first explained the tents in North Point were set up by workers shielding themselves from the wind. “We will make sure there aren’t mainlanders congregating here,” he said.

CLAIM

Amid severe shortages of face masks in the city, online posts alleged that shipments sent from abroad were being held by Customs for political reasons.

RESPONSE

A spokesman for Hong Kong Customs and Excise Department explained on January 28 there was no reason to withhold surgical masks because they were not on the list of prohibited import items.

In an effort to curb pro-democracy protests, Chief Executive Carrie Lam Cheng Yuet-ngor invoked colonial-era powers last October to ban the wearing of masks, including surgical ones, at public assemblies.

While the Court of First Instance declared the anti-mask law unconstitutional in January, the government was appealing the decision.

CLAIM

Images of posters bearing the police logo promoting a giveaway of free masks to “pro-Beijing residents” in the city were circulating online as early as January 23.

RESPONSE

Police said the poster was a fake in a video released on its Facebook page.

CLAIM

Family members of police were said to be receiving masks from the government.

RESPONSE

The force rejected the claim, saying “it must squash such information and remind the public not to be misled”.

CLAIM

Pro-Beijing lawmaker Ann Chiang Lai-wan posted a video to her Facebook page on January 29 that purported to explain how to steam face masks so they could be reused.

The minute-long video from Guangzhou G4, a local news channel from Guangdong province, interviewed a man claiming to hold a PhD in infectious diseases. The man, Wu Meng, claimed that masks could be reused after steaming them at 100 degrees Celsius for 10 minutes.

RESPONSE

Hong Kong’s Centre for Health Protection explained in a Facebook post that masks could not be reused – even after steaming. “Do not trust these rumours,” it added.

CLAIM

Government-issued surgical masks were said to be circulating among Hong Kong residents, with some telling local media they had received or even bought the masks from friends and family in the public sector. One photo showed a box labelled “CSI”, short for Correctional Services Industries, with the name of Yiu Kwok-wai, a pro-Beijing former district councillor of Yuen Long.

RESPONSE

While the government said on January 26 that inmates in the Correctional Services Department (CSD) produced 1.1 million masks a month for distribution to government departments, a February 1 statement confirmed at least some surgical masks had been given to non-governmental groups before the outbreak. That was halted once demand began to rise.

At a February 3 press conference, the city’s leader further clarified that no government-issued masks should be sold to the public. “I cannot explain why they have gone into the market, because this is an anomaly,” she said.

CLAIM

On January 29, online posts in LIHKG, a Reddit-like forum popular with Hong Kong protesters, claimed that Lam’s government donated 20 containers of face masks to mainland China, even as the city’s residents themselves struggled to get hold of the masks.

RESPONSE

The government said in a statement on January 30 that the claims had “absolutely no truth in them”, adding it was negotiating with overseas manufacturers to make fresh supplies available.

CLAIM

The Hong Kong government is sitting on a stockpile of as many as 100 million surgical masks and other supplies.

RESPONSE

The government said on January 26 that the claims were “unfounded”, saying about 1.1 million masks were produced each month by the Correctional Services Department, with the entirety being distributed to police, hospitals and other government departments.