Peru's former President Alberto Fujimori is not eligible to stand in the 9 April presidential poll, the national electoral agency has ruled.
Mr Fujimori has been banned from office until 2011
Officials reiterated a ruling by Congress that he was ineligible for public office until 2011.
He is under arrest in Chile awaiting an extradition hearing after he tried to return to Peru to run for election. His daughter entered his application.
Mr Fujimori's supporters say he intends to appeal against the ruling.
They say the ban on his candidacy is unconstitutional, and 20 of them are protesting by holding a hunger strike outside the national electoral agency's office in the capital Lima.
Earlier, the electoral agency confirmed that 24 other candidates had entered successful applications for April's election - the highest number of candidates in a Peruvian presidential race in more than two decades.
These include conservative Lourdes Flores, former President Alan Garcia and Ollanta Humala, a former army officer who led a failed coup in 2000 against Mr Fujimori, who has risen quickly in the polls in recent months.
Mr Fujimori was arrested in Chile on 7 November as he returned from self-imposed exile in Japan hoping to launch his presidential bid.
He faces possible extradition to Peru on charges of human rights abuses and corruption related to his time in office in the 1990s.
He fled to Japan in 2000 after his government was mired in a corruption scandal, but denies any wrongdoing and says the charges are politically-motivated.
Some 2,000 supporters gathered in the centre of Lima on Friday as Mr Fujimori's daughter, Keiko, registered his application.
The former president is a divisive figure in Peruvian society.
To some he is a saviour of a country on the verge of economic collapse and racked by political violence.
Others see him as a corrupt authoritarian strongman who rode roughshod over Peru's democratic institutions.