Burgas appeal court today upheld the pre-trial detention of a 40-year-old driver from Ravda. Prosecutors say Doychin Petrov tried to smuggle nearly 46kg of high-risk drugs into Turkey, hidden in a secret compartment in a truck's fuel tank.

The haul was 20kg of cocaine and 25.5kg of marijuana. Prosecutors value it at more than 2.2m euros, based on prices used for court purposes.

Customs stopped the truck on September 25 at the Lesovo border crossing, on the lane leading out to Turkey, where it was passing through in transit. The check was part of an operation by GDBOP, Bulgaria's organised crime unit, and the customs agency, who had spent several days working from information gathered and analysed earlier, watching people and vehicles that fit a drug-trafficking risk profile.

An X-ray scan showed unusual density in the outer fuel tank, so inspectors took it off and cut it open. Inside were 41 packages: 24 vacuum-sealed ones holding a green plant material, and 17 rectangular ones wrapped in tape holding a white powder. Field tests came back positive for marijuana and cocaine.

A lead lining covered the packages to make them harder for inspectors to find, according to case files. The hiding spot used the tank's own structure, so the drugs stayed hidden during a normal check. Investigators say the driver looked visibly nervous while the tank was being removed and sent for an X-ray.

Yambol district court, which heard the case first, also ordered the driver held in custody. His lawyers asked for house arrest instead and challenged some of the evidence, pointing out the case file was missing an expert report on the field test and a check sheet for the scale used. By the time the case reached Burgas, an expert report from a physical-chemical test had been added, confirming what the seized substances were, and the court accepted it as extra grounds to back the prosecution.

The appeal judges weighed the seriousness of the charge, the likely sentence and the man's previous conviction. They said there is a real risk he could flee or commit another crime.

The case continues. If convicted, Petrov faces 15 to 20 years in prison and a fine of between 200,000 and 300,000 levs. There is no public word on whether anyone else has been charged over the alleged smuggling route.

The case ranks among the biggest seizures of a combined cocaine and marijuana shipment at Lesovo this year.