12:05The Documentary21/04/2010BBC World Service Duration: 25 minutes Wed 21st Apr 2010, 12:05 on BBC World Service OnlineAvailable for over a yearListen nowLibyan dissident Jaballah Matar disappeared 20 years ago, and his son Hisham is investigating his fate. Razia Iqbal reports.GenresFactualBrandThe Documentary Source: BBC Online