Jawbone said in a court filing wearables market leader Fitbit is under investigation by a criminal grand jury for theft of trade secrets, Bloomberg reported.
The two companies have been involved in legal spats for some time, which started when Jawbone accused its rival of attempts to “steal talent, trade secrets and intellectual property”.
Jawbone cited the criminal investigation in the court filing in support of an argument the details of what was stolen and by whom have still not been resolved, Bloomberg said.
In response, Fitbit noted it is cooperating with the probes in order to demonstrate “once again, that these allegations are without merit”.
Fitbit found itself on the winning side in earlier rounds of the Jawbone dispute, for example with the US International Trade Commission finding in its favour last year.
Bloomberg said Fitbit believes Jawbone’s continuing actions are “based on the almost identical fictional allegations that were fully rejected by the ITC”.
While Jawbone was one of the early success stories in the fitness tracker market, the company has largely fallen by the wayside in recent months – and it is some time since it last updated its product line.
Reports last year said it had (unsuccessfully) looked for a buyer, having ended manufacture of its products and shifted inventory to distributors.
The company raised a significant lump of cash early last year.
While reports suggested Jawbone is looking to move up the value chain into high-grade trackers for medical use, the company has not provided an update on its operations for some time.