A family hiking trip on Mount Fuji has ended with police intervention after a father allegedly left his seven-year-old son alone on the mountain.

The 48-year-old man from Nagoya was climbing the Fujinomiya Trail with his two sons on Thursday when the younger child, an elementary school student, reportedly complained that he was exhausted.

Rather than turning back or stopping to rest, the father allegedly told the boy to wait near the trail’s sixth station before continuing towards the summit with his older son.

The sixth station is about 2500 metres above sea level, with the summit still several hours away.

According to Japanese media reports, the boy was later found sitting alone on a bench near a mountain hut at about 7.40am.

A worker at the hut took the child inside to shelter and contacted police.

The boy reportedly told workers that his father had instructed him to wait for about eight hours. He had no money and was carrying only some snacks and a soft drink, although he was otherwise equipped for the hike.

The father had continued climbing with his older son and was eventually located near the trail’s eighth station.

Police contacted him and ordered him to return to his younger son.

The family was later reunited and the seven-year-old was unharmed.

The incident became particularly concerning as rain began falling and fog started gathering around the mountain.

Conditions on Mount Fuji can change rapidly, with deteriorating weather potentially affecting visibility, footing and the safety of hikers.

Police strongly reprimanded the father over his decision.

“Even if it means having to give up on climbing the mountain together, leaving a child behind is unacceptable,” officers told him, according to Japan Today.

The father reportedly admitted he had made a mistake, saying: “I made a rash decision, and I deeply regret it.”

Authorities have since warned hikers against separating from members of their group, urging them to plan their pace and climbing goals around the person with the lowest level of stamina.

The Fujinomiya Trail is one of the routes used to reach the summit of Japan’s highest mountain, and the journey between the sixth station and the peak can take several hours.

The case has prompted renewed warnings about the risks of attempting demanding mountain climbs with young children and the importance of staying together when conditions can change quickly.