Berlin, Jan 31 (DPA) Germany's government is considering buying purloined files on about 1,500 German taxpayers alleged to be using secret Swiss bank accounts to evade taxes, Berlin officials confirmed Saturday.

Two German newspapers reported Saturday that data on five evaders had been given to Germany as a free sample to test the veracity of the information.

Officials who asked not to be named told the DPA that no decision had been reached yet. Tax authorities could expect to recoup the cost several times over through back taxes and penalties.

The New York Times reported Jan 18 that such data was being offered to Germany by a former Swiss banking executive. But it was not clear at first if he was the source of the new data cache.

The secretive 'offshore' banking industry was rocked in 2008 when client lists from two Liechtenstein banks were betrayed to German, US and other tax authorities, apparently by whistleblower former staff.

A series of rich Germans suffered police raids as their tax scams were exposed and tiny Liechtenstein angrily protested at the damage to its most lucrative sector, operating confidential bank accounts.

Germany, the US and many other nations require their taxpayers to declare annually all their income worldwide, but it has been easy in the past to conceal such income in 'offshore' banks.

Two newspapers, the Frankfurter Allgemeine Zeitung (FAZ) and the Sueddeutsche Zeitung, said the data had been offered to tax collectors in the western state of North Rhine-Westphalia.

Officials said it was up the states, which collect taxes in Germany, rather than the federal government to decide whether to buy the data. The key issue was whether evidence obtained by breaking Swiss law might not be admissible in a German court.

FAZ said each of the five sample cases would lead to one million euros ($1.4 million) in revenue being recovered.

A Federal Finance Ministry spokesman declined comment on the case, but said Germany was regularly offered leaked data from tax havens.