"I thought, am I losing my mind?"

That was the reaction of Oisin Lavelle as he spent two hours watching a mysterious, brightly coloured sphere moving in the sky south-west of Christchurch on Monday night.

Lavelle took footage of the object before it moved away at high speed. On Tuesday night it reappeared and he drove nearer for a better look, and saw three such objects. He said he found the whole experience haunting and would like to know what he saw.

OISIN LAVELLE/SUPPLIED The mystery object filmed above Christchurch.

"I'm quite an open-minded person, but I'm not a UFO buff or a conspiracy theorist or anything.

"I couldn't come up with a logical explanation for it. My gut feeling is, this was not some sort of technology we have on earth," he said.

Did you see these mystery objects? Let us know by emailing newstips@stuff.co.nz

Lavelle, the managing director of a building firm, was letting out his dog Rollo when he first saw the bright lights in the night sky from the deck of his lower Cashmere home. It was just after 10.30pm on Monday.

"I grabbed my camera and tried to get the thing steady and in focus. I just didn't know what to think, it was just so peculiar," he said.

"I just kept watching and filming because I wanted to see what it would do".

Lavelle described the object as a brightly lit perfect sphere. The lights kept changing through a wide range of colours at first, but the colour spectrum narrowed.

As well, up to three dark lines moved across the sphere like rotating bands, perhaps gyroscopically, he said.

When the object eventually sped away at about 12.40am, it was to bursts of bright orange light which silhouetted a dark shape against it. It was gone within 15 seconds.

His wife also looked at the object through the camera lens.

Later, after viewing the footage, Lavelle said he could see it was not a drone, or a jet, or a satellite, or reflected light, or anything else he knew.

When he saw the objects again on Tuesday night, one appeared to be somewhere near Tai Tapu, one further east above Diamond Harbour or off the coast, and the third was further west towards the alps. The change in colours appeared to co-ordinate, Lavelle said.

"The way they were moving, the way they changed colour, it was like nothing I've seen or heard of before."

Airways Corporation, which controls air traffic across New Zealand, said they had no record of any unusual occurrences in the airspace on Monday or Tuesday evenings, and all aircraft movements in controlled airspace were as planned.

The Defence Force said it had no night-time activities at its Burnham Military Camp on those evenings, while the owners of the Christchurch Adventure Park being built on the Port Hills said their drone flying and construction was limited to daytime.

"We are intrigued to hear about it, and we'd love to know what the mystery objects were too," a spokeswoman for the park said.