Anthem singer Lizzie Marvelly's 'worst nightmare'

Popera singer Lizzie Marvelly says her "worst nightmare" happened before last night's Maori All Blacks vs Lions match.

Early in her rendition of the New Zealand national anthem Marvelly can be heard missing a few words, sounding uncertain as she refinds her place in the Maori verse.

A newspaper rugby reporter got stuck into her in a post-match report, accusing her of "messing up".  Others took to social media to slam the outspoken singer, accusing her of not learning the lines.

In a post on social media site Instagram, Marvelly set the record straight.

"We wear in-ear monitors so we can hear ourselves when we're singing at games, and last night mine failed during the song I sang before the game. We switched them over before the anthem, hoping that would fix the problem, but when I got out there to sing they started crackling pretty severely before they cut out entirely," she said.

"In-ears that are fitted correctly have a kind of seal in your ear, so you can't hear anything else. It's a bit like wearing earplugs. When mine went, I couldn't hear anything, and I lost my place in the anthem while my brain tried to figure out what was going on. I ripped them out and found my place and carried on but I was utterly devastated to have been thrown."

Luckily, the cameras were focused on the teams and the crowd when at "the moment everything went wrong", sparing her some embarrassment.

"I'm one of those people who absolutely hates letting anyone down, so I felt that misstep deeply and wished more than anything that I could go back and do it properly (without in-ears!). Thank you for your understanding, your aroha and your fortifying words. I am so very sorry."

She suggested the cause may have been overlapping radio frequencies, and said the Oceania sound team are investigating.

Most responses on both Twitter and Instagram backed the singer, some saying they didn't even notice anything had gone wrong.