Two classic car collectors are engaged in a bitter legal dispute in the UK after 55-year-old Gregor Fisken paid U.S. lawyer Bernard Carl $44 million in 2017 for a 1962 Ferrari 250 GTO (pictured,) but hasn’t received the vehicle’s original gearbox.

The Telegraph reports that Fisken immediately sold the car on to an anonymous collector after he purchased it. Lawyers for the 55-year-old claim that he was under the impression the original gearbox would be sourced and handed over by former owner Bernard Carl.

Speaking in court, Fisken’s lawyer, William Hooper, claimed “Mr Carl undertook to use his best efforts to recover and deliver up the gearbox, in consideration for Gregor Fisken Ltd (GFL) accepting the GTO without it.”

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It is understood that the pair fell out when it emerged that a dealer in the U.S. was in possession of the gearbox and wanted $25,000 to hand it over. Tensions between Fisken and Carl rose as the two tried to have the gearbox delivered to the UK but debated about who should pay for the release fee and shipping costs.

According to Carl, Fisken has refused to collect the gearbox from California and that this has “repudiated” the contract, meaning Fisken no longer holds any title to it. Speaking to the judge, Carl said he has never been opposed to the idea of providing Fisken with the gearbox.

“The gearbox and the GTO are worth more together than apart. It makes commercial sense (to unite them) and I never opposed the idea.”

Carl wants Fisken to hand over a cool $500,000 to cover his costs in locating the transmission.