Startup Donut Lab made a splash at the start of the year with some astonishing — — claims about its solid state batteries. Now Finnish newspaper reports an individual has filed a criminal whistleblower complaint against the company over those claims.

, Lauri Peltola was listed as the Chief Commercial Officer at Nordic Nano — the firm reportedly contracted to handle portions of the manufacturing on Donut’s behalf, and which Donut Lab has . He reportedly filed a criminal complaint that Donut Lab’s promises of energy density and longevity have been overstated and that the company lacks the production capacity previously claimed.

HS suggests it has seen copies of internal communications between Donut Lab and two partner companies, CT-Coating and Nordic Nano. The paper says that CT-Coating’s first-generation battery is the one that Donut Lab has been advertising, and is the model it handed to Finnish national lab VTT to test. But, according to the emails viewed by HS, CT-Coating had abandoned development on that cell in favor of a one still in early development, despite Donut Lab’s in January that it had a technology ready to enter mass production.

Donut Lab CEO Marko Lehtimäki reportedly told HS he had no knowledge of Peltola’s complaint. Nordic Nano CEO Esa Parjanen, meanwhile, denied Peltola’s accusations, saying that his views were not shared by the company and that Peltola had no involvement with Nordic’s battery project. In a joint Donut Lab and Nordic Nano stated they “do not know the exact nature of the complaint” but denied “having committed any crime or misleading investors.” They also describe the complainant (presumably Peltola, though the statement does not name him) as not having “the necessary knowledge of battery technology or the overall picture of the development work.”