A legal battle over use of a smartphone technology has pitted two Silicon Valley leaders against each other.
Keyssa - a start-up funded by Tony Fadell - has claimed its wireless data-transfer tech was stolen by Essential - a smartphone manufacturer founded by Andy Rubin.
Mr Fadell co-developed the original iPod and Nest's smart home kit, while Mr Rubin helped create and develop the Android operating system.
Essential has yet to comment.
Neither of the two entrepreneurs are named in the legal papers filed so far, but their links to the companies involved are likely to ensure the case has a high profile.
The two men briefly overlapped at Google in 2014, where both served as senior executives.Image copyright Essential Image caption
Keyssa was founded in 2008 and has developed a new way to transmit data at high speeds from one device to another.
Its metal-free solution, called Kiss Connectivity, is marketed as being more secure and power-efficient than Bluetooth and wi-fi, and less prone to wear and tear than a wired connection.
Keyssa alleges that it discussed and shared information about its tech with Essential over a 10-month period before the phone-maker opted to use a rival company's chip to connect a camera accessory and dock to its handset.
In doing so, Keyssa alleges, Essential made use of its trade secrets and breached a non-disclosure agreement.
"Keyssa has not been compensated for Essential's use of this guidance and know-how," it said in a statement.
"We are pursuing this action because our attempts to resolve this matter through discussions with Essential have not been successful."
The development coincides with news that Apple faces a $440m (£334m) payout in a separate patent dispute over communications technologies used in its Facetime video chat app and other software.
The sum claimed by Virnetx is about $140m more than last reported but less than the initial award.The latest sum takes account of the fact that a judge has ruled that Apple's infringement was "wilful".