Democratic presidential candidate Michael Bloomberg received loud applause and whoops at the latest TV debate with his rivals – cheers that some said were suspiciously enthusiastic given his lacklustre performance.

The former New York mayor needed a strong showing at the debate to recover from his first appearance with the other candidates in Nevada, which was generally agreed to have been a disaster for his campaign.

However, while his performance was more confident and better received than his last, various commentators noticed that the audience in the room seemed to be cheering Mr Bloomberg on with a vigour and frequency that his words did not warrant.

Their deduction was that the billionaire candidate might have “stacked” the crowd with paid-for attendees, something the campaign denies.

Others said the high cost of tickets may have worked in his favour. Longtime left-wing hero and activist Michael Moore tweeted that “tickets to get in cost up to $3,200. No surprise to see Bloomberg get some cheers. Is there any joy in watching this debate?”

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Some stopped short of accusing Mr Bloomberg directly, but laid into the issue of campaign-aligned audiences and how they can distort what happens in the hall.

CNN’s Chris Cillizza tweeted that “Candidates should not be allowed to try to pack the debate hall with a cheering section who applaud when they open their mouth.

“It's not only annoying but it changes the way people watching on TV perceive answers and the candidates that give them.”

Others, however, have dismissed the notion of a paid-for pro-Bloomberg audience as the beginnings of a baseless conspiracy theory.

Democratic Party communications director Xochitl Hinojosa tweeted that “Candidates get the same amount of tickets. No one is packing the debate hall. This is how conspiracy theories get started.”

Another user, Democratic campaign veteran Tori Taylor, wrote: “There are so many topics worthy of debate. This isn’t one of them — because it’s not true.

“Candidates aren’t allowed to pack the debate hall. They all get the same amount of tickets. That room is filled w/ a diverse group of folks from across South Carolina & the country.”

The Washington Post asked the Bloomberg campaign to provide a list of the people to whom it had given its 15 allocated tickets, and was told they went to organisers, volunteers, and current and former elected officials.