Leftist candidate Pedro Castillo took a slight lead over right-winger Keiko Fujimori, daughter of jailed former President Alberto Fujimori, on Monday as ballots were tabulated from Peru's presidential runoff.

With more than 93 percent of the ballots counted, the schoolteacher from one of Peru's poorest regions had 50.16 percent of the vote compared with 49.83 percent for Fujimori.

The votes remaining to be tabulated are from remote, rural areas - where Castillo in strong - and from Peruvians living abroad, expected to lean toward Fujimori.