The man behind Wellington's bizarre box-cycle has told the story behind the kooky rain cover.

The man beneath the box has spoken of the pragmatic solution that made him an anonymous internet hit.

Since a large, brown cardboard box was spotted riding through central Wellington on Tuesday, the hunt has been on to find the cyclist beneath.

Speaking under the condition of anonymity, Box Man explained how he ended up riding through Wellington under a large cardboard box.

MIRO BZDUCH A mystery Wellington cyclist was snapped earlier this week sheltering from the rain in cardboard box creation.

"It was getting pretty late and I had to get back home to my kids but I had this giant box and I kinda wanted to take it home for the kids to play in, and it was raining.

READ MORE: Wellington cyclist snapped wearing a cardboard box to shelter from the rain

"I had no way of getting it back so I sort of looked at the box and I looked at my bike and I thought, whoa, they are the same size.

"I flipped it upside down, ran out the door and that was about it."

But that wasn't about it as Box Man was filmed cycling with the box and the video became an internet hit.

"It was definitely more funny watching than it was riding it," Box Man said.

A source close to the box understood the man behind it planned a big reveal during a "bike rave" that starts at Pukeahu National War Memorial Park this Saturday night, but even that remains vague.

"It's a bit hard to talk to a cardboard box," the source said.