Rostock, Germany - Four men went on trial in Germany on Friday for attempting to extort money from the Liechtenstein bank LLB by threatening to reveal data on 2,325 suspected tax dodgers.

The trial was adjourned until Wednesday while judges consider six defence motions, including a claim of judicial bias.

Prosecutors retorted that the defence was trying to deliberately stretch out the trial.

The case is expected to revive questions about the ethics of the German BND intelligence service paying 4.2 million euros (6.3 million dollars) this year for another purloined list of customers of a separate Liechtenstein bank, the LGT.

Prosecutors in the northern port city of Rostock are expected to argue that German authorities' buying such a list was legal, but demanding money from Liechtenstein to keep it a secret was a crime.

Liechtenstein, a territory between Switzerland and Austria, insists it is not a tax haven, but its cast-iron bank secrecy has attracted rich people from around the world setting up low-tax trusts.

The four defendants are accused of extortionately obtaining 9 million euros (14 million dollars) from the LLB for returning bank data they obtained in 2005, prosecutors are to allege. The data was allegedly stolen by a bank employee.

The indictment was not read aloud Friday because of the delay, but the prosecutors have made details public in the past.

The quartet is claimed to still possess data on 700 customers of the Liechtensteinische Landesbank (LLB) and have been negotiating via their lawyers for a lower sentence in exchange for its return.

The indictment said the group sought to extort 4 million euros from Liechtenstein for the return of the last block of data.

The leader of the group was arrested last year as he was about to leave Germany and take refuge in Thailand.

On Friday, defence lawyers alleged that somebody had offered to sell a complete set of the court's files on the case to the news media for 2,000 to 3,000 euros. Prosecutors said there would be an investigation of the allegation.(dpa)