"Porsche has identified issues in connection with individual roll-out tests," Porsche said in a statement.

The specific case involves deviations in the measurement of wind resistance values and the corresponding information reported to regulators, the company said.

"The company is continuing its internal investigations in close consultation with the authorities," Porsche said, adding that the problem is not related to engine management software and does not affect vehicle safety.

(Reporting by Tom Sims; Editing by Alexandra Hudson)