Iran said Tuesday it has allowed the crew of a South Korean oil tanker it seized last month to leave the country, according to news reports.

The MT Hankuk Chemi had 20 sailors, including five Koreans, aboard when it was seized by Iran's Islamic Revolution Guards Corps for alleged oil pollution on Jan. 4.

The release comes in a "humanitarian move" by Tehran following a request from the South Korean government, Reuters quoted a spokesman for Iran's foreign ministry as telling state media.

Observers have said the vessel's seizure could be linked to Iran's anger over its assets frozen in South Korea due to US sanctions on the regime. (From news reports)