Turkey on Saturday said two foreigners were involved in businessman Carlos Ghosn's transit through Istanbul as he fled Japan on his way to Lebanon.

"There are two foreigners involved in the transit," Turkish Justice Minister Abdulhamit Gul told CNN's Turk broadcaster during an interview.

He did not provide further details on their nationality or exactly what role they played.

Ghosn, the former Nissan boss, is accused of financial misconduct but he claimed his upcoming trial was rigged before he made his escape from Japan before New Year's Eve.

There is already an official Turkish probe into Ghosn's apparent transfer between private jets at Istanbul's Ataturk Airport.

The investigation is focused on two flights, the first a Bombardier labelled TC-TSR flew from Osaka in Japan, landed in Istanbul at 05.15am and parked in a hangar.

The second was a private jet to Beirut, a Bombardier Challenger 300 TC-RZA, which left 45 minutes later, news agency DHA previously reported.

After seven people were detained earlier this week in Turkey including four pilots, five were formally arrested, Gul said, adding that the prosecutor's probe continued.

The minister also said that there had been no formal judicial request from the Japanese authorities in relation to the incident.