The victims, including reporters, were killed after their convoy was attacked in southern Maguindanao province.
More than 100 suspects are standing trial for murder, some of them members of the powerful local Ampatuan clan. They deny the charges.
Amnesty International says the trials risk becoming "a mockery of justice", informs Report citing BBC News.
"Justice delayed is justice denied," said Hazel Galang-Folli, Amnesty's Philippines researcher.
"Five years after the Maguindanao massacre, the cases are still inching through the Philippine court system and not a single person has been held to account."
The 23 November 2009 massacre is alleged to have been carried out by the Ampatuan clan to stop a political rival from running for the post of governor.