Leading royal commentators have come under fire after they were filmed giving their views about Prince Harry and Meghan Markle’s performance in their eagerly awaited interview with Oprah Winfrey for an undisclosed fee, days before they had seen it.

Four commentators, including the Queen’s former press secretary Dickie Arbiter and CNN’s royal commentator Victoria Arbiter, gave interviews to a fake news company created by YouTuber pranksters Josh Pieters and Archie Manners on Friday, two days before the interview was aired. They had been told it would be shown immediately after the CBS programme was broadcast.

In the prank, the commentator and editor-in-chief of Majesty magazine, Ingrid Seward, said of the Duchess of Sussex, “to my mind this was an actress giving one of her great performances – from start to finish, Meghan was acting”, despite not having seen the interview.

Royal commentator Richard Fitzwilliams said it was “not a balanced interview”, accusing Oprah of giving the couple “an easy ride” and being “totally sympathetic”, and saying that Meghan “used extremely strong language to describe her relations with members of the royal household”.

The YouTubers also duped some of the experts into discussing false topics supposedly covered in the Oprah interview, including Meghan’s support for the Balham donkey sanctuary and refusal to have the coronavirus vaccine.

The pair have become infamous for their high-profile pranks, tricking celebrities including Little Mix’s Perrie Edwards into interviewing for a Borat film, influencers into promoting gravel, and nominating reality TV star Gemma Collins for a Nobel peace prize.

The pair told the Guardian they had “wondered whether people would say things that weren’t necessarily true to purely jump on the buzz of this Harry and Meghan interview, and it turned out that they would”.

“To me, it’s like asking a football commentator to give me 90 minutes of voice-noting on [a match they haven’t seen]. It’s such a ludicrous premise,” Manners said, insisting they deliberately duped commentators rather than news correspondents, and did not intend the video as an attack on the press. “These people charge news organisations for their views, and their views do shape public opinion.”

The duo insisted that they weren’t leading the commentators on or “feeding them lines”, simply asking “broad stroke questions that you simply cannot answer if you have not seen the interview”.

“We then decided that having done that we would push it a bit further and come up with the silliest things we could imagine, almost to give them a chance,” Manners said. “We did say, ‘in the interview Meghan says she wouldn’t take the vaccine’. We would hope that a royal expert who would presumably know a lot about Meghan would at that point go, hang on, that seems somewhat unlikely.

“It also, I would argue, seems somewhat unlikely that Meghan Markle is going to discuss the Balham donkey sanctuary. We only ever brought up those facts when they were so far-flung that to comment on them would be ridiculous.”

The duo also denied claims they had told the commentators only relevant comments would be used, and said the commentators had signed release forms which gave the YouTubers full rights to use the video how they wished. They also insisted the edit was “incredibly fair”.

“I think it’s quite a commentary on the modern world,” said Pieters. “You need to really think about the information you take in, and try and verify it and do some research into what you hear and read … I think this video does point to that in a way to say, sometimes things you see aren’t always as they seem.”

When asked about his role in the video, Fitzwilliams said he “obviously didn’t know it was a sting” and that the comments had been “used out of context”.

“The arrangement was that the comments would be broadcast depending on what was in the interview, so nothing inappropriate would have appeared from anyone contributing,” he said. “We had by then seen two trailers. Together with the hype, it promised to be pretty toxic and define Harry and Meghan’s relationship with the royal family for the foreseeable future.”

“This sort of pre-record, filing material in advance, is frequently done for various news stories, obituaries etc so journalists have instant comment in the event of breaking news. There is nothing whatever dishonourable in it,” he added.

Dickie Arbiter said that the approach from Beneath the Fold, the name of the false media company, “alleged to be a legitimate invitation for a fast turnaround, pre-recorded interview commissioned by a UK network, to be aired on Monday 8 March 2021.

“This was deliberately misleading and a ‘scam’. I commented only on clips already in global circulation, but my interview was edited so as to imply I was speculating on the full-programme interview. I was not speculating. I do not speculate.”

Representatives for the other commentators have been approached for comment. Archewell, the Duke and Duchess of Sussex’s organisation, declined to comment.