A man walks past the main gate of the Tokyo district court where former US special forces member Michael Taylor and his son Peter, who allegedly staged the operation to help fly former Nissan chief Carlos Ghosn out of Japan in 2019, arrived at the court in Tokyo on Monday. Photo: AFP

An American father-son duo who helped former Nissan chief Carlos Ghosn flee Japan were sentenced to 20 months and two years in prison by a Tokyo court on Monday.

The sentences are the first to be handed down in Japan in the Nissan saga, which began with former auto tycoon Ghosn's shock arrest in 2018 on financial misconduct allegations.

Former US special forces operative Michael Taylor was jailed for two years, while his son Peter received a sentence of 20 months. "This case enabled Ghosn, a defendant of serious crime, to escape overseas," chief judge Hideo Nirei said.

"Both defendants pulled off an unprecedented escape," the judge added, noting that there was no prospect of Ghosn - an international fugitive in Lebanon - returning to Japan.

The Taylors, who faced up to three years in prison, did not contest their role in what US prosecutors described as "one of the most brazen and well-orchestrated escape acts in recent history."

The pair both apologized in previous hearings at which Japanese prosecutors had sought a sentence of two years, 10 months for Michael, and two years, six months for Peter. Their defence lawyers had argued that a suspended sentence was appropriate given their remorse, and asked that the 10 months they were in US detention before being extradited should be considered in sentencing.

The Taylors arrived in Tokyo in March after losing a battle against extradition.

At their first hearing, in June, prosecutors described the almost-cinematic details of the operation - including that Ghosn was hidden in a large case with air holes drilled into it to slip past security at an airport. 

Describing the experience recently to the BBC, Ghosn said the half-hour in the box waiting for the plane to take off as "probably the longest wait I've ever experienced in my life."

Ghosn himself remains in Lebanon, largely beyond the reach of prosecutors despite active investigations in several countries. In May, he was questioned by French investigators in Lebanon over a series of alleged financial improprieties.

But he was only heard as a witness, and would need to be in France to be formally indicted.