German customs authorities have seized two containers containing more than 14,000 files on account holders from the Cayman Islands arm of Swiss private bank Coutts as part of a wider investigation into the financial affairs of German nationals.

German customs authorities have seized two containers containing more than 14,000 files on account holders from the Cayman Islands arm of Swiss private bank Coutts as part of a wider investigation into the financial affairs of German nationals.

The bank confirmed to this publication that the containers had been seized as they were en route to a secure storage facility in Switzerland from the Cayman Islands, where the bank recently closed its offices.

More than 1,000 cartons, containing 14,000 files, were seized from a ship in Hamburg harbour that was on its way to the company’s data centre in Geneva.

Last year, Coutts took the decision to sell its Cayman trust book of business as part of a strategic review by the private bank to dispose of certain non-core trust businesses and focus on its international trust business in Jersey.

Coutts said that the shipment of the papers was in line with its document retention policies and that there was no reason to believe that the contents of the container had been interfered with.

The private bank said that it was standard practice to transfer papers in this way and that the documents were being held in a secure environment.

"We are not aware of any investigation into our trust company or its papers and we are working with the authorities to allow these papers to continue on their way," Coutts said in a statement.

Offshore tax evasion remains a serious problem for countries and jurisdictions worldwide, with vast amounts of funds deposited abroad and sheltered from taxation when taxpayers fail to comply with obligations in their home countries.

In recent years, German authorities have stepped up investigations into alleged tax evasion by wealthy citizens.

In 2012, German tax authorities purchased confidential information about clients of Coutts to see if they were hiding money in Switzerland.

Officials in North Rhine-Westphalia paid for a compact disc containing the names of 1,000 rich Germans who had accounts with Coutts in Zurich.

In the past, the state has bought other CDs containing client names of Swiss-based banks. The purchases have been followed by tax investigations against hundreds of German taxpayers.