Nearly half of UK adults online have been exposed to false or misleading information about coronavirus in the last week, a report from Ofcom has said.
New research by the media regulator found many people are also struggling to tell what is true or false in relation to Covid-19.
It follows calls from senior MPs and other organisations to better hold social media companies to account over disinformation.
Culture Secretary Oliver Dowden spoke to major social media companies Facebook, Twitter and Google on Wednesday to discuss how they could clamp down further on content, as a range of false claims about the virus continue to spread online.
He welcomed progress made and the companies agreed to continue to work together to address disinformation and fake news, at speed, and to intensify the collaboration.
According to Ofcom, since the lockdown began, 35% of adults online have seen the false claim that drinking more water can flush out the infection, while around 24% saw false claims that gargling with salt water or avoiding cold food or drink can stop the virus.
Although more than half (55%) say they are ignoring false claims – with 15% using fact-checking tips – one in 14 said they were forwarding on disinformation.
Forty percent of those surveyed also said they found it hard to determine what was true or false about the virus, a figure which rises to more than half (52%) of 18 to 24-year-olds.
Younger people were also found to be following official advice less closely, Ofcom said, with only 43% of those aged 18-24 saying they were following hand-washing advice very closely.
According to the study of 2,000 people, almost all of adults online in the UK are getting news and information about Covid-19 every day, with one in four doing so 20 or more times a day.
The survey found that the BBC’s TV, radio and online services (82%) were the most common places people turned to for news on the pandemic, followed by other broadcasters (56%).
Official sources such as the World Health Organisation (WHO), the NHS and the Government were the next most popular sources of information, used by 52% of people.
Strikingly, the figures suggest that more people are turning to social media than newspapers – with 49% saying they used social media platforms to get news compared with 43% who looked to the papers.
Fifteen percent of those polled also said they used close messaging groups, such as WhatsApp or Facebook Messenger, to get information.
Social media platforms and other internet services have taken some steps to curb the spread of misinformation, such as promoting official advice and banning some types of content, but critics have said much more needs to be done.
Last week, a number of phone masts were damaged across the UK after theories spread online that 5G mobile technology was linked to the spread of Covid-19.
This was despite there being not a single piece of evidence suggesting a link, and numerous scientists describing such a process as “both a physical and biological impossibility”.
Yih-Choung Teh, Ofcom’s group director for strategy and research, said: “People are turning to public authorities and traditional broadcasters for trusted information about Covid-19, and the vast majority say they’re closely following official advice.
“With so much false information circulating online, it’s never been more important that people can cut through the confusion and find accurate, trustworthy and credible sources of news and advice.”
Ofcom said it has created a set of resources on its websites to provide people with guidance on how to navigate news and information about Covid-19.
These include debunking misconceptions and harmful claims, as well as tips on how to find reliable content and identify fact from fiction.