Tokyo prosecutors will probe how former Nissan Motor Co. Chairman Carlos Ghosn jumped bail and fled Japan for Lebanon, a senior prosecutor said Sunday, as the foreign minister suggested he left the country in a "fraudulent manner."

Diplomatic sources said that in October, the Lebanese government informally asked Japan to hand over Ghosn. Beirut has denied any involvement in last month's escape by Ghosn, who holds Brazilian, French and Lebanese nationality.

"It is regrettable as he ignored our country's legal procedures and the act could amount to a crime," Takahiro Saito, deputy chief at the Tokyo District Public Prosecutors Office, said in a statement after Ghosn fled to Lebanon last week to escape what he claimed is a "rigged" Japanese justice system.

"We deal with matters appropriately by collaborating with related institutions to identify what has happened with swift and proper investigations," Saito said.

Foreign Minister Toshimitsu Motegi told reporters that Japan would seek cooperation from relevant countries over the matter. "We have no record of (Ghosn's) embarkation. It is believed he left the country in a somewhat fraudulent manner."

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The Wall Street Journal reported Friday that Ghosn was packed into a case typically used for concert audio equipment and sneaked onto a private jet at an airport in Osaka Prefecture late last month. He was accompanied by private security contractors on the flight to Turkey, it said, citing people familiar with the matter.

Japanese Justice Minister Masako Mori said in a statement that she has instructed Japanese immigration authorities to tighten procedures for people leaving the country.

The prosecutors confiscated Ghosn's French, Lebanese and Brazilian passports, which had been held at his lawyers' office in Tokyo, but it has emerged that he has a second French passport in his possession.

Ghosn, who was facing trial for alleged financial misconduct, apparently left his home in Tokyo and departed the country from Kansai International Airport in Osaka on a private jet on Dec. 29.

The 65-year-old former chief of the Nissan-Renault auto alliance was released on bail in April on conditions that included a ban on foreign travel after prosecutors' appeal against the court decision was rejected.

Saito said the reason the prosecutors sought Ghosn's detention was that there was a risk of him destroying evidence as he had abundant funds and many overseas bases, making it easier for him to escape. He also has significant influence in and outside Japan.

"It is clear that the defendant's rights were fully guaranteed, as he was able to communicate freely with lawyers after he was released on bail," Saito said.

"The escape is an act of merely trying to flee from punishment for his crime and there is no way that his act can be justified," he added.

In Beirut, diplomatic sources said the Lebanese government had been considering asking for Ghosn to be handed over and in October sounded out Japan.

Lebanon planned to submit a formal request later that month by sending a minister to Tokyo to attend a ceremony marking the enthronement of Emperor Naruhito. But it was unable to send the representative to the ceremony due to protests in Lebanon, the sources said.

Beirut then made the request on Dec. 20 when it received a diplomatic mission from Tokyo, headed by Senior Vice Foreign Minister Keisuke Suzuki, a Lebanese government source said.