Roeland Hugo Gerrit (Roel) van Duijn (born 20 January 1943) is a Dutch politician, political activist and writer.

After graduation he moved to Amsterdam to study political science and history, later turning to law.

Although Van Duijn informed the police authorities afterwards and pressed charges against Baank the latter was not prosecuted.

On 15 February 1975, a bomb was placed in the Venserpolder metro station, which was under construction, by a group of right-wing radicals including Baank.

The authorities assumed left-wing squatters had planted the bomb and Van Duijn was the only member of the local government who refused to sign a statement blaming them.

In 1977 he became an organic farmer and started a cheese farm in Veele (municipality of Vlagtwedde) and had two sons.

In 2009, it was shown that Van Duijn had been shadowed by the General Intelligence and Security Service for decades.