Leftist candidate Pedro Castillo has won the most votes in Peru's close-run presidential run-off election.

With all ballots now counted, Mr Castillo has just over 50% of the votes - 44,000 more than right-wing contender Keiko Fujimori.

But Mr Castillo cannot be declared the winner until electoral authorities have finished processing a slew of legal challenges brought by Ms Fujimori.

She has claimed electoral fraud, but has not provided any detailed evidence.

Electoral observers, including the Organisation of American States, have said they have found no irregularities. Castillo's Free Peru party has also rejected accusations of fraud.

More than 18.8 million Peruvians cast their votes in this year's race - a turnout of nearly 75%. Observers have said it could take weeks to deliberate over Ms Fujimori's legal challenges and formally announce a winner.

But Mr Castillo, a 51-year-old former school teacher and union leader, has already declared victory.

"Tonight should not only be one of hullabaloo and joy, but of great responsibility," he told supporters in the capital, Lima, according to RPP news. "Today the real battle begins to end the great inequalities here in our homeland."

He also called on election authorities to call the race and "respect the popular will".

Meanwhile Ms Fujimori, who is running for president for a third time, acknowledged the release of the count, but said it was important to wait for the results from the pending investigations.

"We trust the authorities, yes, but, above all, we trust the popular will," she said.

Keiko Fujimori is the daughter of former President Alberto Fujimori, who is in jail serving a 25-year sentence for crimes including corruption and human rights abuses.

Ms Fujimori herself is being investigated for alleged corruption and money laundering, claims she says are politically motivated. She spent a total of 13 months in jail between 2018 and 2020, when she was released on parole.

Last week, in a surprise development, prosecutor José Domingo Pérez requested that Ms Fujimori be returned to pre-trial custody, alleging that she had been in contact with a witness, violating the terms of her parole.