Police discovered a marijuana plantation in northeastern Switzerland while using Google Earth's internet satellite mapping software to search for an address.
The 7,500 square metre plantation was hidden in a cornfield in canton Thurgau.
Officers were using Google Earth to find the location of farmers suspected of involvement in a drug ring.
"It was an interesting chance discovery," said Norbert Klossner from Zurich police's specialist narcotics unit.
As part of a wider probe, 1.2 tonnes of marijuana and SFr600,000 ($519,000) in cash were seized and another plantation was also discovered in the canton.
Police have arrested 16 people of different nationalities and are expected to formally charge them in February with trafficking the drug.
The gang is alleged to have sold up to seven tonnes of hashish and marijuana between 2004 and 2008 and earned up to SFr10 million a year.