Pitchers Kim Kwang-hyun, Lee Yong-chan and Jeong Cheol-won were all investigated by the Korean Baseball Organization (KBO) after media allegations against the trio emerged last week.

The players admitted drinking alcohol during the preliminary round of the tournament in Tokyo but denied they did so on the evenings before South Korean defeats.

The team lost 8-7 to Australia on March 9 before a 13-4 defeat to hosts Japan a day later.

Lee said he met a friend at a Korean restaurant on March 7 and Kim and Jeong said they had drinks after the Japan match on March 10.

The KBO checked the players' credit card statements and interviewed bar staff as part of its probe.

It said Kim additionally visited a bar on March 7 and March 11, with Jeong joining him on the later date.

Lee also visited the same bar on March 11, but not with the other two players.

Kim has been fined KRW5 million (£3,000/$3,800/€3,500) and told to carry out 80 hours of community service.

Both Lee and Jeong have been fined KRW3 million (£1,800/$2,300/€2,100) with 40 community service hours.

All three players apologised in front of the cameras after attending a hearing and were removed from the active rosters of their club sides.

They all denied that they had been accompanied by women when out drinking.

The KBO does not have a rule which can penalise players for drinking while with the national team, according to Yonhap.

But it can penalise players for "not acting with honour and dignity" while representing the country, with their actions at the World Baseball Classic falling under this criteria.

South Korea won matches against the Czech Republic and China at the tournament but it did not prevent them from exiting in the group stage for the third time in a row.

Drinking alcohol is treated seriously in Korean sport.

In 2019, Olympic medallists Kim Tae-yun and Kim Cheol-min were among five speed skaters who were suspended by the Korea Skating Union for two months for drinking at their training centre in Seoul. 

Two South Korean baseball players were then removed from the country's Tokyo 2020 Olympic squad after breaking social distancing rules during the pandemic.

Second baseman Park Min-woo and pitcher Han Hyun-hee did not travel to Japan after meeting friends for drinks in Seoul.

South Korea won Olympic gold in baseball at Beijing 2008.