The parents of a one-month-old baby who died of prolonged starvation have been detained in Russia amid claims that they are believers in “feeding on sunlight”.

The baby’s 33-year-old mother, Oxana Mironova, is under investigation for causing death by negligence. She was placed under house arrest for two months by a judge.

The father, influencer Maxim Lyutyi, 43, was separately detained for resisting police. He is a blogger known for promoting radical eating habits such as eating only raw food and feeding on the sun’s energy.

The couple founded a club called “The Living Man”, which focuses on improving people’s health and helping them deal with personal problems.

Preliminary investigations reveal the baby died from severe exhaustion after Lyutyi tried to instil his eating habits in him, Russian TV network Zvezda News reported.

Russian law enforcement agencies said the couple tried to change the baby’s diet to prana eating, where people go without food and water for a long time and “feed on sunlight”.

The child was taken to a hospital near Sochi after he was suspected of suffering from pneumonia and emaciation.

Lyutyi’s social media posts show more of his bizarre beliefs, such as accusing Swedish activist Greta Thunberg of being an actress and claiming 3D printers were a part of life in the 19th century.