Eight wealthy German nationals are being investigated on tax charges by the South African Revenue Service in co-operation with the German authorities.

The investigation is the extension of the probe into what has become known as the Liechtenstein tax scandal, which involves hundreds of rich people putting their money in the principality's LGT Bank to avoid paying taxes in their home countries.

The investigation was launched in February by the German government into 700 of its wealthy citizens after it purchased a disk from a former LGT Bank employee containing data. The investigation - the largest and most complex into tax evasion in Germany - has since expanded, with probes also being carried out around the world.

The South African tax authorities estimate that it could be losing R64-billion to tax havens annually. Eight wealthy, retired Germans living in the Western Cape of South Africa, were being investigated at the request of the German authorities, a spokesman for SARS was quoted as saying.

Meanwhile, Germany’s pursuit of tax evaders with secret assets in Liechtenstein could gain momentum after a man facing charges related to handling bank data from Liechtenstein gave documents to authorities.

State prosecutors in Rostock, northern Germany have received account data for about 1,850 people with assets at Liechtensteinische Landesbank, the Alpine state’s second-largest bank, lawyer Astrid Denecke said.

Ms Denecke is one of two lawyers representing Michael Freitag, a German national, who is on trial before a Rostock court, charged with trying to blackmail LLB into paying €13 million ($20 million) for the return of secret account data stolen by an employee.

Should prosecutors deem the documents valid, they could greatly extend the scope of the inquiry, spearheaded by prosecutors in the north-western city of Bochum. They are investigating 350 people and have a further 420 in their sights for hundreds of millions in allegedly unpaid taxes.