"The anger is being sustained by the government’s flagrant obstruction of the investigation," RSF said in a statement. "Lasantha Wickrematunge’s name and memory will not disappear and, in that sense, those who were behind his murder made a mistake."
RSF asked candidates at the January 26 presidential elections to pledge to probe the editor's murder and other serious press freedom violations in recent years.
The government of President Mahinda Rajapakse has denied involvement in the killing although his newspaper has said the administration was responsible.
The New York-based Committee to Protect Journalists (CPJ) also used the first anniversary of the death of Wickrematunge to draw attention to dozens of killings and attacks against journalists under Rajapakse