The number of individuals and firms under investigation in Germany's cum-ex tax scandal has risen from around 400 to more than 800 over an eight-month period, according to a new court filing.

The figure pertains to 68 preliminary proceedings in the ongoing cum-ex scandal, which started when a number of organisations were alleged to have claimed twice on tax rebates, costing Germany around €5 billion.

According to German newspaper Handelsblatt, in response to the growing number of cases and the fear that some will fall outside the statutory limitation period, German Finance Minister Olaf Scholz said he planned to extend the statute of limitations on particularly serious tax evasion from currently 20 to 25 years.