The driver of the Audi A8 in the crash on Chelopeshko Shose road in Sofia, which killed four people, is to leave custody and be held under house arrest. The Sofia Court of Appeal ruled on 17 September, but the decision was not made public at the time.
Trayan Filipov, one of the so-called "Kalashnikovs", had appealed against a June court decision that refused to ease his detention. The judges found there was not enough evidence of a race between the cars. They also said there was not enough evidence to link Filipov's actions to the deaths of the four people.
Investigators are working on the theory that the cars were racing. They say the cars were going at nearly 150 km/h in a 60 km/h zone.
The crash happened on 5 June at 7.37pm. After the collision, one of the cars smashed into the windows of a city bus. Seventeen people were hurt.
Neither driver has a Bulgarian driving licence, and their Czech licences were issued a year ago. Police have known them for years over offences that include driving without a licence and speeding.
Two of the dead were travelling in the cars. Two others were Indian citizens who had lived in Bulgaria for about a year. Their employer said they were conscientious, responsible people who had settled into life in Bulgaria.