A British man has reportedly been killed by a Canadian man during a spiritual ceremony at a jungle retreat in Peru they had both been attending.
Unais Gomes, 26, was stabbed to death by Joshua Andrew Freeman Stevens, 29, from Canada, in self-defence, Normando Marques, police chief in the region near the jungle city of Iquitos, said.
Video footage posted online showed Stevens being taken into custody and the aftermath of the incident.
According to Reuters, witnesses said Gomes tried to stab Stevens with a kitchen knife during a "bad trip", but the Canadian stabbed him in the chest and stomach with the same knife.
Both men are understood to have taken the hallucinogenic plant brew ayahuasca, a mixture of Amazonian plants and vines that contains dimethyltryptamine.
While it causes psychedelic experiences, it is not normally associated with violence. Ayahuasca ceremonies have become increasingly popular in the Amazon among tourists, where the brew is taken under the supervision of a guide.
The incident took place at the Phoenix Ayahuasca retreat, which according to its Facebook page is a "safe and supportive place to experience plant medicines and explore the true nature of the self. Ayahuasca is a purgative psychedelic that removes spiritual and emotional blockages."
BuzzFeed News has contacted the centre for comment.
A UK Foreign and Commonwealth spokesperson said: "We can confirm the death of a British national in Peru on 16 December 2015. We are in contact with the local authorities and are providing consular assistance to the family at this difficult time."