Lorde's surprise appearance at a Grey Lynn dance party was just a trick

Attendees at a Grey Lynn dance party have been tricked into believing Lorde showed up for a secret performance.

The Kiwi pop star was reported to have shown up at a No Lights No Lycra dance event in Grey Lynn last night to perform her song Green Light.

But she wasn't there. In fact, she's currently thousands of kilometres away eating Creme Eggs with her mum in London.

The event bills itself as "a weekly hour of dance freedom in total darkness" and is held at the Grey Lynn library on Mondays from 7pm.

It had been teasing an appearance by a "special guest" for last night's session.

Several attendees believed the special guest was Lorde, who reportedly ended the session by performing her latest single, Green Light.

Kiwi musician Nadia Reid took to Twitter to thank 'Lorde' for her performance.

She told the Herald the Lorde imposter was convincing and was surprised to hear the singer was in London.

"It was kind of weird because the PA distorted at the start. It was quite confusing what was happening," she said.

"It sounded like Lorde and you could see this black figure."

Others took to Facebook and Twitter after falling for the ruse.

"My Lord(e), the 'secret special guest' didn't disappoint!," wrote one dancer on Facebook.

Another called her a "secret ninja".

"Thank you Ella (for) surprising us like that and your voice was amazing live in the little hall in the dark," wrote another.

When you go to No Lights No Lycra and the last track is Lorde performing Green Light LIVE 💃🏽💃🏽

— the prij (@theprij) March 27, 2017

But just six hours ago, Lorde posted a picture to Instagram saying she was in London.

Lorde's mother Sonya Yelich-O'Connor has also replied on Twitter, calling the reports "weird" and confirming the singer is in London.

weird - we are in London rn - me n @lorde 🇬🇧

— Sonja Yelich (@sonjayelich1) March 27, 2017

And Lorde also commmented, calling it "deeply fake news" but "quite cute".

No Lights No Lycra organiser Craig Neilson took to Facebook to reveal the fake Lorde as Auckland music student Hannah Grace Horsfield.

Lorde last performed two songs, Green Light and Liability, on Saturday Night Live and she and her mother have posted regular updates on social media from New York ever since.

Lorde's second album Melodrama is due for release on June 16.