The documentary maker cleared by regulators of misleadingly editing a Channel 4 programme about extreme Islamic preachers is considering legal action.
David Henshaw, the managing director of Hardcash Productions which made the Dispatches film Undercover Mosque, said he was still "very, very angry".
"I really don't like the libel courts and believe in a world of free comment. I don't mind abuse, but Hardcash's reputation has been severely damaged and it was a good reputation," Henshaw said. "The Ofcom judgment is great and if anyone bothers to read it they'll realise this was a bloody good programme. But damage was done that day in August, huge damage."
The programme, which took nine months to make, went undercover in several mosques in the Midlands and showed examples of preachers calling for homosexuals to be killed, espousing male supremacy, condemning non-Muslims and predicting jihad.
Henshaw said: "A lot of these mosques were in terms of their public image very moderate and were apparently committed to inter-faith dialogue. Yet what was going on on a very regular basis was pretty uncompromising, hardline, antisemitic, homophobic, misogynist preaching."
The police referred the case to Ofcom after investigating 56 hours of rushes from the documentary for evidence against the preachers.
Henshaw said he told police there was unlikely to be a case. "They came to us for the rushes and we said we honestly didn't see any offence had been committed," he said. "We thought it was profoundly anti-social, disturbing and unpleasant but not necessarily illegal. Nonetheless, they pressed ahead and got a production order."
It was "something of a surprise" when the West Midlands police issued a press release eight months after the programme was transmitted in January, accusing its producers of selective editing and distortion.
"Our reputation was really seriously damaged by this. We're only a small company but we've done quite a lot in the last 15 years," said Henshaw.
A Channel 4 spokesman said: "The film has been widely recognised as an important piece of journalism that was plainly in the public interest. Investigative journalism of this type is increasingly rare because it is difficult, risky and costly - the authorities should be doing what they can to help it survive, not seeking to undermine it."