Tehran is claiming that Seoul is holding seven billion U.S. dollars in Iranian funds hostage. 

According to Reuters, Iranian government spokesperson Ali Rabiei made the argument at a live-stream news conference on Tuesday, denying that its seizure of a South Korean oil tanker amounts to hostage-taking. 

Rabiei said that if there is hostage-taking, it is “Korea’s government that is holding seven billion dollars which belongs to us hostage on baseless grounds.” 

On Monday, the South Korean-flagged vessel carrying 20 sailors was seized by Iran's Revolutionary Guards Corps in the Strait of Hormuz in Gulf waters with Iran citing alleged environmental pollution issue as the reason for the seizure. 

According to a high-ranking official of the South Korean Foreign Ministry, Iran earlier denied the speculation that the vessel seizure was intended to gain leverage in handling the Iranian funds frozen at South Korean banks under U.S. sanctions. 

Some seven billion dollars of Iran's oil money is frozen in two South Korean bank accounts, after the U.S. tightened sanctions on Iran upon its 2018 withdrawal from the Iran nuclear deal, effectively banning Seoul's indirect trade with Tehran.