VIENNA (AP) — Austrian police have announced the breakup of an international gang dealing in phony health products and say insufficient postage provided the major lead.

British, Hungarian and Austrian police were involved in the sweep that culminated Monday in eight arrests, including the suspected head of the scam in Vienna, police said. Searches netted 130,000 euros (more than $170,000) in cash and about 1 million fake pills, worth about 10 million euros (more than $13 million.)

They told reporters that investigations gathered steam in 2012 after a package was sent back from Austria to Spain due to insufficient postage, and the drug store falsely listed as the sender went to police.

Interior Minister Johanna Mikl-Leitner calls the bust “the greatest blow against the trade in counterfeit medicines Europe-wide.”