Doctors revealed his condition was likely caused by a heart attack after his brain suffered a lack of oxygen.
Intelligence reports on Otto’s time behind bars claim he was being subjected to ‘daily beatings’.
There are now calls for Donald Trump and other global leaders to tackle the awful conditions faced by prisoners in the hugely-secretive country.
Following a report from the U.N., along with satellite photos of the camps, it is estimated that hundreds of thousands of political prisoners have perished in these camps over the past five decades, according to The Philadelphia Inquirer.
In the report, it states that the nation deliberately treated prisoners badly to try and lower their prison population.
The report found:
The inmate population has been gradually eliminated through deliberate starvation, forced labour, executions, torture, rape and the denial of reproductive rights enforced through punishment, forced abortion and infanticide.
The unspeakable atrocities that are being committed against the inmates of the political prison camps resemble the horror camps that totalitarian states established during the 20th century.
WARNING: Distressing footage.
When news of Otto’s death broke, U.S. President Donald Trump blasted the country.
The U.S. once again condemns the brutality of the North Korean regime as we mourn its latest victim.
The U.S. once again condemns the brutality of the North Korean regime as we mourn its latest victim. Video: https://t.co/Rvm11ZbPk7
— Donald J. Trump (@realDonaldTrump) June 20, 2017
Many believe that if the U.S. can shine a light on these conditions in prisons, then Otto’s death may not have been in vain.