A segment of animated footage promoting the 2012 Olympic Games in London has been removed from an official website following fears it could trigger epileptic seizures.

The jigsaw-style logo is made up of four jagged pieces that form "2012" in a series of colours, and was meant to engage people with a dynamic, modern and moving style, organizers said.

While the logo itself does not pose a health hazard, 18 people have reported having epileptic seizures after viewing the animated footage.

A section depicting a diver plunging into a pool that has a multicoloured rippled effect triggered the most complaints.

"I'm really shocked," said Simon Wigglesworth of Epilepsy Action, a British health charity. "They know flashing lights can cause problems."

The footage failed a test used to measure whether photosensitivity levels in animated TV footage are safe for people with epilepsy, said Prof. Graham Harding, an expert in clinical neurophysiology who developed the test.

"It fails the Harding FPA machine test, which is the machine the television industry uses to test images," Harding told the BBC.

"And so it does not comply with Ofcom guidelines and is in contravention of them."

At the launch of the logo earlier this week, the chair of the organizing committee praised the concept.

"We don't do bland, this is not a bland city," said Steven Coe, adding they did not want a dull, corporate logo on a polo shirt that people end up wearing for gardening in a year.

'Catastrophic mistake'

The committee paid more than $840,000 for the ad that has increasingly become unpopular.

"I wouldn't pay a penny for such a catastrophic mistake," said Ken Livingstone, mayor of London, questioning why organizers would ask for such a design.

As of 1 p.m. ET on Wednesday, more than 40,000 people have joined an online petition calling for the ad to be scrapped, and there are bids for an alternative promo.

Games organizers were hoping the new brand would raise $4 billion to stage the games.

While there is no proof the ad has triggered seizures, organizers are re-editing the footage.

About 0.6 per cent of the Canadian population has epilepsy, according to Epilepsy Canada. In some cases, the seizures can be controlled by medication, but other times, surgery is needed.