CNN  — 

A middle-aged couple in Austria received quite a surprise one morning when a parcel that was supposed to contain dresses bought online from a retailer in the Netherlands turned out to contain nearly 25,000 ecstasy tablets.

The unnamed Austrian woman, 58, mistook the purple pills for decorative stones, police said, but on closer inspection her husband, 59, realized they were probably stimulants and returned the package to their local post office in Linz, Upper Austria.

The ecstasy tablets, pictured, were intended for Scotland.

“The originally planned cozy breakfast was quickly over and to the horror of the couple, it turned out that, though one of the packages did contain the two dresses, the second however had 24,800 Ecstasy tablets worth about €500,000,” said a statement from Upper Austria police.

“The (post) office was equally astonished, which is why the police, and subsequently the narcotics department of the City Police Command Linz, was informed.”

According to Austrian police, the 24,800 pills were worth around €500,000 ($550,000), though Police Scotland told CNN that the likely UK value of the drugs was around £165,000 ($205,000).

The Netherlands is one of the world’s largest drugs producers and earlier this year Dutch customs officials reported that the amount of ecstasy and amphetamines being sent in the post had tripled from 137 kilograms (302 pounds) in 2016 to 460 kilograms in 2018.

Following an investigation by Linz’s drugs squad it transpired that the package was intended for Scotland. Police Scotland and the UK’s National Crime Agency (NCA) are jointly investigating the matter.

An NCA spokesperson told CNN: “This is a live investigation and enquiries are ongoing.”

In July, police searched premises in Glasgow, Scotland but no arrests were made.

Additional reporting by Christian Streib.