Invercargill's mystery pooer remains at large, despite a "tasteful" CSI investigation into the code browns.

Poos were found floating in swimming pools in Invercargill's Splash Palace Aquatic Centre on six consecutive Friday evenings in February and March.

The poos created a media storm, with multiple theories put forward as to who the defecator may be.

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However, the mystery pooer went underground after the sixth Friday and has never been publicly identified.

Splash Palace aquatic services manager Pete Thompson said on Wednesday he was not convinced the pooing had been malicious.

He believed it may have been done by a kiddie in a water sports club who had health issues.

A crew from Melbourne radio station Nova 100 visited the Invercargill swimming complex about a month ago and did an "Invercargill CSI" take-off.

"It was done tastefully," Thompson said.

A school of thought floating around at the time of poo-gate was the culprit may be a kid in either a swimming or water polo club which used the pools each Friday night.

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Thompson said the actions of the pooer, or pooers, had resulted in the aquatic centre becoming infamous for the wrong reasons.

"It's not the sort of thing you want to be known for. It got very tedious in the end, and all jokes aside, it was hugely disruptive to the operation of the pool."

The public had been understanding and the repeated pooing had not put people off using the pools, attendance figures have shown.

Invercargill Mayor Tim Shadbolt said the publicity generated by the pooing was not particularly good publicity for the city.

"Phantom pooer in the pool isn't the sort of headline you want around the country."

He believed the code browns attracted global attention because it was such a mystery which still has not been solved.

"Who knows when they will strike again."

Even with poos, Invercargill's swimming pools were better than some in the country, the mayor said.

"We had our local government conference in Rotorua and the pools might not have had poos in them, but they were a lot more smelly than our one ever was."