The voluntary disclosure scheme with which undeclared savers could receive a lower fine has resulted in considerably higher tax revenues.

Between 2002 and 2018, approximately 12 billion euros in hidden assets were still reported to the tax authorities, which resulted in 2.1 billion euros in taxes, according to a study by the Central Planning Bureau (CPB) on Tuesday.

The invested capital comes mainly from Belgium, Luxembourg and Switzerland and mainly comes from men aged around 65 who are entrepreneurs.

More than 27,000 households have invested an average of 435,000 euros.

The 5 percent richest households in particular have made use of the scheme.

Because a larger part of the wealth is known to the tax authorities, the share of the richest thousand households in the total wealth distribution has grown from 8.8 percent to 9.4 percent.

According to the CPB, the voluntary disclosure scheme also generates more tax income in the long term.

This is because the volunteer's box 3 capital grew by about 60 percent, and they will continue to pay tax on it in subsequent years.