The prosecution will Wednesday indict Korean-born German scholar Song Doo-yul for allegedly serving as a member of the Politburo of North Korea's ruling Workers Party, in violation of the National Security Law which bans any unauthorized contact with Pyongyang.

The indictment comes nearly two months after the philosophy professor of Germany's Muenster University returned home in late September, ending a 37-year self-imposed exile to protest Seoul's authoritarian governments in the past few decades.

Prosecutors have charged Song with meeting with late North Korean leader Kim Il-sung in 1991 before being appointed an alternate Politburo member and serving as the 23rd highest member of the funeral committee for Kim Il-sung in 1994.

Song is accused of visiting North Korea over 20 times since 1973.