Renault SA is aiming to reach in about a week the first conclusions to its internal probe into whether the pay packages of Carlos Ghosn, along with the French carmaker's other top managers, were properly disclosed to shareholders, according to people familiar with the matter.

The ongoing investigation focuses on their salaries and other benefits at Renault, where Ghosn remains chief executive officer and chairman, said the people, who asked not to be named because the information isn't public. The probe is being led by Eric Le Grand, a former head of security who was recently appointed as an ethics and compliance officer, and another Renault insider, Claude Baland, a 68-year-old former top civil servant, they said.

Ghosn is in custody in Japan after his Nov. 19 arrest on allegations of underreporting his income at Nissan Motor Co., which has since ousted him as chairman. While he remains at the helm of Renault, he has been replaced on an interim basis. Tension within the Franco-Japanese partnership held together by Ghosn for two decades has all but exploded into the open since his incarceration.