A British backpacker died after drinking a hallucinogenic herbal concoction during a tribal ritual while travelling around Colombia, an inquest has heard.

Henry Miller, 19, who was described in court as a curious young man, died after taking part in a ritual during which he took yagé, which brings on vivid hallucinations and supposedly spiritual experiences.

The teenager from Bristol also consumed scopolamine, which comes from plants of the nightshade family, the inquest in Flax Bourton near Bristol was told.

Maria Voisin, the senior coroner for Avon, described Miller as a “happy and healthy young man” who had been preparing to study English at the University of Brighton. She concluded his death had been accidental.

During the inquest it emerged that the tribe had held its own hearing in which it said there had been no intention to harm Henry, but the shaman Guillermo and his wife, Mama Concha, were ordered to undergo punishment with nettles together with their son and his friend.

The coroner said she would write to the Foreign Office to highlight the findings of the inquest. “We know there are a lot of students and young people travelling in that part of the world and I will be making a report,” she said. “I will be phrasing it in such a way to encourage some standard message warning about this ceremony.”

Ignatius Hughes QC, representing the Miller family, said they wanted other travellers to be aware of the dangers of taking part in such ceremonies. “Other young travellers might benefit from being made aware of the small but real dangers inherent in this perfectly lawful practice,” he said.

“We understand from the Foreign and Commonwealth Office that consideration is being given to a standard message to travellers when they visit the FCO website for that part of the world.”

Miller travelled to Bogotá on 14 February 2014, and was staying in a hostel in the south of Colombia run by a retired Belgian police officer. His last contact with his family was on the evening of 22 April before he set off to attend the tribal ceremony that led to his death. He had told them he had already attended a ceremony at the shaman’s cabin two days previously and had drunk three cups of yagé, but felt nothing.

A fellow traveller, Christopher Deardon, said Miller was a curious young man with a big heart, and that he had drunk a small cup of herbs to facilitate the effects of the yagé at the second ceremony.

“None of us knew what this was. Then we all drank our cups. I threw up after about 15 minutes and when I came back Henry seemed to be feeling the effects straight away,” he said.

Deardon said Miller left to return to the hostel but the following morning police arrived at the camp and said he was missing.

The tribe held its own trial in July, attended by a representative of the Foreign Office.

The representative reported that the trial had heard Henry was given a single leaf of scopolamine before the ceremony began. “They repeated it was never their intention to harm Henry with their medicine and the values of their community was to share with others,” the representative reported.

“They claimed this case was a first for their community and they have now realised about not sharing with foreigners without some thought about the process.”

Miller’s body was found beside a rural road outside Mocoa, the capital of Putumayo province.

William Burroughs documented the effects of yagé in his book The Yagé Letters, in which he wrote to the poet Allen Ginsberg of his mind-altering experiences.

• This article was amended on 31 August 2018 to remove a personal detail.

