The prankster who invaded the pitch to line up with the All Blacks for the national anthem in Wales says he was originally planning to join the haka - but spotted the perfect moment to move earlier.

Brit Daniel "Jarvo" Jarvis is today back in London, reflecting on his latest sporting prank which saw him join the New Zealand line-up, donned in full All Black gear - and an arm bandage to add authenticity as a fully professional rugby player.

Jarvo - who has previously donned cricket whites and joined two England v India cricket tests and stripped down to Speedos to be an Olympic diver - says he'd wanted to be an All Black "because they are the biggest, best rugby team in the world".

"They are the best to watch - that's it really."

He and two friends arrived at the Principality Stadium in Cardiff slightly later than expected on Saturday evening local time, and saw the All Blacks on the field, training in their orange Adidas practice gear.

"I panicked. I thought have they changed their kit? When I saw them run onto the field, I thought 'Thank God'."

He was originally planning to join the haka, perhaps unaware of its cultural importance. "I don't know the haka moves. I was going to do my own crazy moves."

But as the All Blacks were gathering to line up for the anthem, a steward walked from the bottom of the stands, up some stairs. The 33-year-old saw his moment to strip down and head to the turf. "I don't pause. If I act confidently enough, it usually works."

No one pursued him as he jogged, player-like, onto the field, and video shows one official was looking the other way as Jarvo moved behind him to join the All Blacks.

Jarvo's YouTube video shows Richie Mo'unga, Sevu Reece and Brad Weber all cotton on to him pretty quickly.