Wellington - The American singer who botched the New Zealand national anthem before a rugby league Test against England apologised Tuesday and said she deserved to be ridiculed.

Crystal Collins told New Zealand's Radio Sport she felt "horrible" after her version of "God Defend New Zealand" was dubbed the "worst" rendition of their national anthem.

"I felt horrible. I would have rather sang it a capella, as that was how I was rehearsing," said Collins, who sang the New Zealand and England anthems before the Test in Denver on Saturday.

She appeared to miss her cue and then stumbled through the anthem without appearing to know the words or tune, leading television commentator Glen Larmer to call it "the worst rendition" he had ever heard and New Zealand Rugby League boss Greg Peters described it as "disgraceful".

"I accept all the ridicule I am getting. All I am getting is warranted," Collins told Radio Sport.

Collins said she had rehearsed the anthem, which has versions in New Zealand's two official languages - English and Maori.

But when the anthem came on with a backing track, she could not hear the monitor.

"I could hear nothing at all. I was waiting for the introduction, but there was none," she said.

"I would like to apologise to you and the citizens of New Zealand."

Collins then sang a near perfect rendition of the Maori version on air.