Imelda Marcos - The widow of former dictator Ferdinand Marcos, who was deposed in a "people power revolution" in 1986. The first couple was accused of plundering billions of dollars from state coffers and overseeing vast human rights abuses.
Joseph Estrada - Former president kicked out of office halfway through his six-year term in 2001 amid a popular uprising triggered by allegations he was corrupt. Convicted in 2007 of plunder while in office, but was pardoned by his successor.
Gloria Arroyo - Succeeded Mr Estrada in 2001 and served as president for nearly a decade. Her successor and current president, Benigno Aquino, has made her his top target in a war on corruption, and had multiple charges laid against her.
Ryan Luna - Went into hiding last month after being indicted for the murder of a political rival's wife in 2007 elections.
Rodrigo Duterte - Veteran politician known as "The Punisher" for his tough stance against crime. Rights groups accuse him of encouraging vigilante groups that summarily execute petty criminals, including children.
Ronald Singson - A scion of a prominent political family in the northern Philippines, he was sentenced three years ago to 14 months in jail in Hong Kong for cocaine possession. He is running in a province that for decades has been controlled by his father, Chavit, an admitted illegal gambling kingpin.
Clara "Fems" Reyes - Wife of Joel Reyes, the former governor of the island province of Palawan. He is accused of masterminding the murder of an environmental activist in 2011. Her husband and brother-in-law are on the run after being charged over the murders.
Jose Rodriguez - Mr Rodriguez is on trial for the alleged rape of a 12-year-old girl in 2010. He denies the charges.
Cipriano Violago - Went underground last week after a judge issued an arrest warrant for him for allegedly killing a policeman. He denies the charge, according to an aide.
Johaira Midtimbang Ampatuan - She is the wife of Zaldy Ampatuan, one of the alleged masterminds of the Philippines' worst political massacre, the killing of 58 people in 2009.
