Funnyman Rhys Darby has taken a swipe at Kiwi comedy reviewers for spoiling the punchlines.

The stand-up comedian and actor, who shot to international fame as hapless manager Murray in Flight of the Conchords, criticised "lazy reviews" on his Facebook page last week.

"If you're going to review live comedy shows, make sure you don't give away the jokes word for word in your review! ... amateurs," he wrote.

"Talk about the premise, yes, even the set-ups but don't try and get laughs from the reader by essentially stealing the material."

Darby was upset by reviews of shows in the New Zealand International Comedy Festival, which features almost 90 acts in Auckland and Wellington until May 24.

He said British and US reviewers knew what they were doing, but "live comedy hasn't been around as long in NZ so we're still getting to grips with how to review it, I guess".

His comments were backed by most of the people who responded. Comedian James Nokise, appearing in The Adventures of Jimi Samoa at the festival, said reviews should include a spoiler warning at the top.

Westie comedian Ewen Gilmour told the Herald on Sunday giving away the punchline was like "telling kids there's no Santa".

Speaking from Los Angeles yesterday, Darby was unrepentant, describing offending reviewers as "lazy" and "rude" for getting laughs by "plagiarising" comedians.

"There is a way to review live comedy and that's not the way. If I don't stand up and say it no one will. Comedians won't say it because they'll end up getting a bad review, or they'll be too scared."

Darby, who starred with Jim Carrey in Yes Man and Philip Seymour Hoffman in The Boat That Rocked, said he no longer relied on stand-up and had to worry less about reviewers.

"I'm sort of beyond all of that now, so I can stand up. A lot of the comedians jumped on the bandwagon and were quite happy I mentioned that. It's just a polite thing because we need to work together. As comics, we need reviewers and they need us."

Darby isn't appearing at the comedy festival, but produced two shows through the company he runs with wife Rosie Carnahan.

He will appear at the Winter Festival in Queenstown next month after shooting his first movie lead, opposite Sasha Alexander of hit TV show NCIS.

"It's fabulous," quipped Darby, whose stand-up DVD Imagine That is an international bestseller. "The emphasis is all on me. I'm in most of the scenes."

Darby wondered initially if he could carry the film for two hours, but said it was perfect for him. "It really showcases all of my skills. I can bring my own play on to the script as well."

He said US cable network HBO had commissioned a third series of Flight of the Conchords. "We're discussing it right now, in fact, whether the guys want to do another one. One's been ordered but it's up to the boys.

"They've got another week and a half and they finish their big US tour and then they will probably take a moment to work out whether they want to continue or not. So that's the big question still yet to be answered, I'm afraid."