A man in his 20s was airlifted from Mount Fuji, then rescued again from its steep slopes just days later after he returned to find his phone, according to media reports.

Police said the Chinese university student, who lives in Japan, was found Saturday by another off-season hiker on a trail more than 3,000 meters above sea level.

"He was suspected of having altitude sickness and was taken to the hospital," a police spokesperson in Shizuoka Prefecture said on Monday.

Later, officers discovered the man was the same one who had been rescued on Mount Fuji four days previously, broadcaster TBS and other media outlets reported.

Police could not immediately confirm the reports, which said the man — having been rescued by helicopter on Tuesday — returned on Friday to retrieve his mobile phone, which he forgot to bring with him during the first rescue.

It was not known whether he was able to find his phone in the end, said the reports, citing unnamed sources.

Mount Fuji, an active volcano and Japan's highest peak, is covered in snow for most of the year.

Its hiking trails are open from early July to early September, a period when crowds trudge up the steep, rocky slopes through the night to see the sunrise.

People are dissuaded from hiking outside of the summer season because conditions can be treacherous.

The symmetrical 3,776-meter mountain has been immortalized in countless artworks, including Hokusai's "The Great Wave." It last erupted around 300 years ago.

In a bid to prevent overcrowding on Mount Fuji, authorities last year brought in an entry fee and cap on numbers for the most popular Yoshida Trail.

Starting this summer, hikers on any of Mount Fuji's four main trails will be charged an entry fee of ¥4,000 ($27).