Apple has patented a design for a digital video camera that could potentially compete with the rugged portable cameras made by GoPro.
The news sent GoPro's stock tumbling.
GoPro shares dropped more than 12 per cent on Tuesday after reports of the patent surfaced on tech blogs and financial wires.
Apple has not announced any plans for the patent, which covers a design for a remote controlled, digital camera that can be attached to a helmet, surfboard or scuba mask.
But as first reported by the blog Patently Apple, the company's application to the US Patent and Trademark Office says Apple's design improves on aspects of GoPro's camera.
Apple says GoPro's camera "can cause excessive wind resistance and presents a high profile that is more susceptible to damage."
Representatives for Apple and GoPro did not immediately respond to requests for comment. Patent office records show Apple first applied some time ago for the patent, which was granted on Tuesday.
But one tech analyst cautioned against reading too much into the filing. "Apple develops and patents lots and lots of technology all the time. Only a fraction of it ever sees the light of day in commercial products," said Jan Dawson of Jackdaw Research, who tracks consumer tech products.
Apple had developed sophisticated camera technology for its iPhones and iPads, said Dawson, who doubted the company would want to sell a stand-alone camera unless it could be tied in with its broader family of products and services.
Still, the news seemed to make some GoPro investors nervous.
"Anytime Apple enters a market, it can be bad news for existing players," Dawson said.
Go Pro's shares ended down $US6.91 to $US49.87.
Apple shares gained US97c, or slightly less than 1 per cent, closing at $US110.22.
