MUNICH -- German police have arrested Porsche's powertrain development boss, Joerg Kerner, in connection with parent Volkswagen Group's diesel scandal, sources said.
Kerner is being held on remand as he is seen as a flight risk, the sources said.
Earlier this week German prosecutors searched around 10 premises in Bavaria and Baden-Wuerttemberg as part of their inquiries into emissions manipulations.
They said they were investigating three suspects including a management board member, a member of Porsche's higher management and a suspect who is no longer employed at Porsche. No names were released.
Kerner, who is now in custody, joined Audi from Robert Bosch in 2004. He built up Audi's engine and transmission electronics design, software and functional development division. Audi has been accused of first developing the software that enabled VW to rig up to 11 million diesel engines to hide high emissions.
Kerner is regarded as the confidant of former Volkswagen Group CEO Matthias Mueller, who was Porsche CEO before taking the top post at VW.
Kerner worked closely with VW Group's former top engineer Wolfgang Hatz, who was arrested last year.
The latest raids result from information given to prosecutors by former Audi manager Giovanni Pamio, the Sueddeutsche newspaper reported Friday. Pamio was arrested then released last year. The engine developer has testified against colleagues and is a key prosecution witness.
The management board member under investigation is research and development chief Michael Steiner, the Sueddeutsche reported.
In a letter to staff, Porsche CEO Oliver Blume said: "We reject these allegations and will do our utmost to clear up the matter."
Earlier this year, prosecutors widened an investigation of Audi, which developed a 3.0-liter V6 diesel engine that was used in about 80,000 VW, Audi and Porsche models found to have been equipped with illicit software.
Reuters contributed to this report