The Austrian couple ended up with 24,000 ecstasy pills although they ordered two dresses online.
The police were investigating this unexpected package, and they said the drug was worth 500,000 euros.
The couple from Linz received two packages from their online shopping. One package contained the clothes they were waiting for from the Netherlands, the other was unusually heavy.
When his wife opened it, she saw a colored material in transparent bags. She initially thought those were pebbles for decoration.
But it was suspicious to her husband, so he returned the unexpected package to the post office. That post office called the police shortly after.
Investigators eventually discovered some important details. Someone obviously made a mistake and shipped the drug to Austria instead of Scotland.
Scottish police have tracked down a customer and arrested him. Their Dutch counterparts are still trying to find out who sent the package.