Jo Brand’s joke about throwing battery acid at politicians was inappropriate for a Radio 4 comedy show, the BBC has concluded, although it has dismissed claims from Nigel Farage that she was inciting violence.

The comedian made the comment on the talkshow Heresy, which sets out to provoke and make claims that go against the consensus.

When discussing political figures, including Farage, who had been targeted with milkshakes during the European elections, Brand said: “I’m thinking: why bother with a milkshake when you could get some battery acid?”

She swiftly added that she was joking and insisted she did not like the trend of throwing milkshakes over politicians. “That’s just me. I’m not going to do it. It’s purely a fantasy, but I think milkshakes are pathetic, I honestly do, sorry.”

Few listeners complained when the programme was first broadcast in June and the BBC initially stood by Brand. But the comment was soon picked up by rightwing blogs and pro-Brexit websites, which spread the story on social media and turned it into a row about editorial standards at the BBC.

Within days Downing Street was calling for an explanation of why the joke had been broadcast, the Metropolitan police briefly considered launching an investigation, and Brand herself said it had been a “somewhat crass” comment. As a result, the BBC edited it out of catch-up editions of the programme.

The BBC’s executive complaints unit concluded that in context the “wider message from the episode of the programme was an argument for more civility in political discourse, not less”, and it recognised Brand’s contribution was not intended to be taken as face value. Despite this, it ruled that the joke went beyond what was appropriate for the show.

The complaints unit said: “In the right context and with the right treatment, there is no subject matter which should be beyond the scope of comedy.”

But the incident has raised concerns among comedians.Several told the Observer they feared throwaway comments being taken out of context and shared online where they could be misinterpreted.