The UN-backed investigation into the assassination of former Lebanese Prime Minister Rafik Hariri is making good progress, the lead prosecutor said.

Daniel Bellemare, the Canadian chief prosecutor for the tribunal, arrived in Beirut on Wednesday for a seven-day visit with top government officials, the United Nations reports.

Bellemare told reporters following a meeting with Lebanese President Michel Suleiman that the investigation into the assassination was "making progress and proceeding at full pace."

Hariri and 21 others were killed when a massive explosion ripped through his motorcade in downtown Beirut in February 2005.

A statement from Bellemare's office stressed the importance of moving forward with an unfettered investigation to bring the perpetrators to justice.

"He emphasized that the process he is leading is purely evidence-driven and that the people of Lebanon deserve nothing less than an outcome that cannot be overcast with doubts about the credibility and the integrity of the justice rendered by the tribunal," the statement continued.

The Special Tribunal for Lebanon at The Hague, Netherlands, was formed when a UN investigation found Lebanese proceedings were flawed and Syria, which was blamed for the assassination, was complicating the investigation.

The tribunal, which adopted formal procedures in March, is the first such body to examine the crime of terrorism. Proceedings are expected to last at least five years.

(AFP)