TOKYO - A man in his 20s from Kyushu died after consuming too many caffeinated drinks, according to a forensic study conducted by Fukuoka University.

According to China's Xinhua news agency, Japan's Health, Labour and Welfare Ministry said it was the first such case reported in Japan, stating that "we had never heard of fatal caffeine intoxication".

Japanese media also reported that although a piece of what was likely to be a caffeine pill was extracted from his stomach, results of the forensic analysis concluded that his death was most likely caused by consuming too many caffeinated drinks.

The deceased reportedly drank highly-caffeinated drinks to stay awake during his job at a 24-hour petrol stand.

Scientists from the forensic medicine faculty at Fukoka University added that as there was no signs of a deliberate overdose, they considered the man's death to be the result of an accident.

In terms of caffeine consumption, Japan's Food Safety Commission at the Cabinet Office, states that three cups of coffee a day for a healthy adult and a 350-milliliter can of cola for children between four and six years old is an "adequate" amount.

While fatal incidents of caffeine overdose have not been previously reported in Japan, there have been several reported deaths from caffeine overdose in the United States. In November 2013, the US Food and Drug Administration (FDA) began an investigation into whether the beverage called 5-Hour Energy was linked to 13 deaths reported in the United States.