Former Nissan Chairman Carlos Ghosn, right, walks behind his lawyer Takashi Takano as he leaves the Tokyo Detention Center in Tokyo. File picture: Kyodo News via AP

Tokyo - Japan's justice minister on Sunday slammed former Nissan Motor chairman Carlos Ghosn's escape to Lebanon while out on bail pending trial as "unjustifiable."

Japan had no records of Ghosn's departure from the country, Justice Minister Masako Mori said.

Ghosn, the former head of the Renault-Nissan-Mitsubishi Motors alliance, was believed to have left Japan using "unlawful methods," Mori said in the first official public statement on the stunning flight from justice, the details of which remain shrouded in mystery.

Ghosn, who was awaiting trial over financial misconduct charges, said in a statement after arriving in Lebanon that he escaped "injustice and political persecution" in Japan.

The prolonged detention of Ghosn drew international criticism as he spent 108 days in custody following his arrest in Tokyo in November 2018.

Japan's relatively long detention before indictment is criticized as "hostage justice" at home and abroad.

Ghosn was also subject to stringent bail conditions in Japan, including restrictions on where he could live and a ban on overseas travel. He was not allowed to see his wife without special permission.

"Our country's criminal justice system guarantees the basic human rights of individuals and is carried out properly to reveal the truths of cases," said Mori in defence of the system.

"It is regrettable as [Ghosn] ignored our country's judicial procedures and his act is equivalent to crime," Takahiro Saito, deputy chief at the Tokyo District Public Prosecutors Office, said in a statement on Sunday.

The office will launch a "swift and proper investigation" to determine how he escaped, Saito said.

Ghosn apparently left his home in Tokyo around noon (0300 GMT) on December 29 and departed Japan from Kansai International Airport, 400 kilometres west of the capital, on a private jet shortly after 11 pm on the same day, broadcaster NHK reported.

NHK reported on Sunday, citing unnamed sources, the airport did not conduct pre-flight X-ray checks on large cases loaded onto a private jet, which is thought to have carried Ghosn, because they were too big to fit into an X-ray machine.

Airport officials often do not conduct X-ray scans of baggage for private jets on the orders of aircraft operators or pilots, NHK said.

Meanwhile, Lebanese authorities have told dpa that Ghosn entered Lebanon legally on a valid French passport. He is said to have changed planes in Istanbul.

Turkish private operator MNG Jet said two of its planes were used to help Ghosn escape and blamed an employee for leasing the jets without the company's knowledge.

Turkish police have arrested seven people on allegations they aided Ghosn's escape.

Tokyo said Interpol had issued a wanted notice, even though Lebanon does not have an extradition treaty with Japan.

Ghosn, who holds Lebanese, French and Brazilian citizenship, is expected to be questioned next week by a Lebanese judge about the charges he faces in Japan.

dpa