Swiss authorities are holding a person in custody in connection to a data theft, believed to concern Credit Suisse, while the ex-Julius Baer banker who gave data to WikiLeaks is also being held for questioning.

The Swiss prosecutor has taken one person into custody as part of an investigation into data theft, which is understood to be linked to information stolen from Credit Suisse Group and later sold to German officials.

Meanwhile, in the separate case concerning ex-Julius Baer banker Rudolf Elmer, a Zurich court has ruled he should be held on remand for police questioning over possible breaches of Swiss law, reports said.

In the matter thought to concern Credit Suisse, the Swiss Attorney General’s office in Berne has revealed it is holding someone, but has not directly stated the link to Credit Suisse, although this connection is understood to be correct.

As the matter is being handled by the Swiss government, the bank could not comment further.

A spokesperson for the Office of the Attorney General of Switzerland confirmed to WealthBriefing that the investigation was being carried out, but said no further details could be given at present, as the department’s investigations are carried out according to secrecy rules enshrined in law.

Early in 2010, stolen information reported to include the names of 1,100 German Credit Suisse clients was sold to authorities in Dusseldorf, the capital of the German state of North Rhine-Westphalia. For this, the authorities were said to have paid €2.5 million (around $3.4 billion).

Furthermore, this was not the only instance of authorities paying for stolen bank data, with the UK and Germany purchasing data stolen from Liechtenstein's LGT, and France acquiring data stolen from HSBC in Switzerland. The matter has caused diplomatic spats at times.

Since the financial crisis brought the issue of tax evasion to the fore, as Western governments became heavily indebted, governments have shown an increasing willingness to pay for and use such stolen data. There are worries that, in doing so, they are creating a market for this information, and encouraging disgruntled employees to view data theft as a lucrative option.

Just last week, a former Julius Baer banker, Rudolf Elmer, handed over data to the "whistle-blowing" website WikiLeaks. Although Elmer has gone down a different route than approaching the authorities, his use of client data to try to damage his former employer is understood to follow the termination of his contract under conditions that fell foul of his demands. Elmer was convicted by a Swiss court last week on charges of coercion and breaching bank secrecy, and fined SFr7,200.

Elmer would appeal the court's decision within 10 days, said a statement dated 22 January on the office of defence lawyer Ganden Tethong's website. Elmer was taken into custody by police last Wednesday evening after he handed over computer discs to WikiLeaks earlier last week. The former Julius Baer banker indicated that the CDs contained details of as many as 2,000 offshore bank accounts.

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