Spanish police have raided a house in a Madrid suburb, arrested two people and seized 40,000 doses of a psychoactive substance traditionally used by South American shamans.

The substance yaje — or ayahuasca in Quechua, the ancient Inca language — is derived from a hallucinogenic jungle vine used for centuries in religious and healing ceremonies.

Investigators were alerted to its suspected distribution by an organization in the Las Rozas suburb, the Interior Ministry said in a statement Monday.

Three minors were among 21 people taking part in a ceremony when police raided the house in late December. The agency said the estimated value of the seized drug was $1.63 million.