The Sofia Appellate Court ruled Tuesday to keep behind bars alleged Bulgarian mobster Anton Petrov aka "The Hamster."

He was arrested at the end of June 2012 and charged with organizing a crime group dealing with prostitution.

The magistrates ruled that there is reasonable doubt that Petrov dealt with such activity and the group could be designated as a conspiracy one. They rejected the claims of the defense council that some of the witness testimonies were hearsay.

The decision is final and cannot be appealed.

At the end of June, two women working in a fashion model agency and one man were detained by police at the Sofia international airport. They were interrogated as witnesses.

Later, the Bulgarian police arrested two men who allegedly took part in the organized crime group by collecting money from the prostitutes. One of them has a crime record and the other one is a fashion agency owner.

The authorities have found out that the money was then given to 39-year-old Anton Petrov.

Petrov, along with his driver and two other individuals, were nabbed in the aftermath.

The "Hamster" is also among the defendants in the "Octopus" high-profile criminal case.

The detainees in the "Octopus" case were initially charged with organizing a prostitution ring, drug trafficking, money laundering, racketeering, tax fraud and embezzlement.

In the summer of 2010, the prosecutor declared that it was impossible to solve the case with one trial and opened two trials against a total of 25 defendants, deploying a team of three prosecutors.