Switzerland’s finance minister, Hans-Rudolf Merz, has fiercely defended the country's banking secrecy rules, while fresh allegations were made of widespread tax evasion by German taxpayers. Mr Mertz described pressure from neighbouring states as unacceptable and labelled comments by some of Switzerland's harsher critics impertinent, according to media reports of his speech in the Swiss parliament. He denied the country was a tax haven, and added that authorities had been at the forefront in the fight against money laundering. Switzerland has been gradually introducing a withholding tax on interest made in Swiss bank accounts belonging to European Union taxpayers. Speaking to parliament on Wednesday, Mr Mertz said Switzerland could not be blamed for people who try to avoid higher tax rates in their own countries. Mr Merz said there were no signs that the German tax evasion investigation targeting accounts in Liechtenstein would have a direct impact on Switzerland. Meanwhile, tax authorities in Baden-Wuerttemberg, Germany, have been offered data on 30,000 bank accounts held by Germans in Switzerland, the German state's finance ministry said, Thomson Financial reported. The data offered by the unnamed informer is believed to contain evidence of tax evasion by investors from across Germany, though it is unclear at this stage how significant the information is, a ministry spokeswoman said. Federal authorities recently launched a major investigation into claims that scores of high-earning Germans have evaded taxes by hiding money in accounts in Liechtenstein.