An ex-general who was ruled out of the running in Indonesia's presidential race after finishing third in initial round voting has petitioned for a Supreme Court review of the poll.
Wiranto, who stood for the Golkar party of former dictator Suharto, said his demand was related to a dispute over millions of votes declared invalid due to the "dual punching" of folded ballot papers that were subsequently reinstated.
The former armed forces commander, who won 22 percent of votes in the July 5 poll behind Susilo Bambang Yudhoyono's 33 percent and President Megawati Sukarnoputri's nearly 27 percent, said the legal action was not a case of sour grapes.
"This is not some kind of fabricated decision. This is not an emotional decision in response to that problem, but it is to maintain the credibility of the election's result," he told a press conference.
Former US president Jimmy Carter, one of hundreds of foreign poll monitors, described the double-punching as a serious mistake, but said it did not favour any one candidate.
Wiranto said he would seek a separate judicial Constitutional Court review on "various problems" that occurred during and after the ballot which he claims cost him about 3.4 million votes.
Such legal challenges would intensify political uncertainty in Indonesia, which has been preoccupied with elections for almost the entire year. Separate legislative polls were held on April 5, with Golkar topping the vote.
In a separate development ahead of September 20 runoff vote between Megawati and Yudhoyono, the National Awakening Party (PKB), Indonesia's third largest party, backed down from an earlier endorsement of Yudhoyono.
The move comes amid heavy horse trading as the remaining two candidates compete for supporters of those eliminated.
PKB deputy chairman Mahfud Mahmuddin said Thursday a decision to back Yudhoyono made by a meeting of the party's regional executives a day earlier was not binding, according to the Detikom online news service.
PKB was established as the political arm of the country's largest Islamic movement, Nahdlatul Ulama, whose former chairman is standing as Megawati's running mate.