Radio New Zealand apologises for 'pro-Kremlin garbage'

The head of Radio New Zealand has apologised for publishing what he called "pro-Kremlin garbage".

A journalist has been placed on leave after it was discovered several online stories about the war in Ukraine had been altered in favour of Russia.

Chief executive Paul Thompson said about 250 stories had already been forensically reviewed since staff were alerted on Friday.

Sixteen stories have been edited and thousands more are to be scrutinised.

"It is so disappointing. I'm gutted. It's painful. It's shocking," he told RNZ's Nine to Noon programme. "We have to get to the bottom of how it happened."

Mr Thompson announced there would be an external review of the organisation's editing processes.

A statement on RNZ - which is state-owned - said after uncovering issues in the 16 stories, they had now been republished with corrections and editor's notes.

Mr Thompson has apologised to listeners, readers, staff and the Ukrainian community.

"It's so disappointing that this pro-Kremlin garbage has ended up in our stories," Mr Thompson told Nine to Noon. "It's inexcusable."

The edited articles' claims included that Russia had illegally annexed Crimea after a referendum - but Russia's occupation of Ukraine's southern peninsula is not recognised by Ukraine and the wider international community.

The United Nations has passed a resolution, emphasising the illegitimacy of the referendum.

Former New Zealand Prime Minister Helen Clark tweeted that she expected better from the public broadcaster.

"Extraordinary that there is so little editorial oversight at Radio New Zealand that someone employed by/contracted to them was able to rewrite online content to reflect pro-Russia stance without senior staff noticing," she wrote.

RNZ's website is one of the most viewed news sources in New Zealand.