Otto Warmbier, the US student released in a coma last week after nearly 18 months in detention in North Korea, died on Monday, his family informed, reported Agence France-Presse (AFP) news agency.

The 22-year-old was medically evacuated to the United States last Tuesday, suffering from severe brain damage. He died six days later surrounded by relatives in his hometown of Cincinnati, Ohio. Doctors last week revealed that he had suffered severe neurological injuries.

Pyongyang claimed Warmbier fell into a coma soon after he was sentenced last year, saying the college student had contracted botulism and been given a sleeping pill.

The young man was on a tourist trip when he was arrested and sentenced in March last year to 15 years hard labor for stealing a political poster from a North Korean hotel.