A special commission in Haiti has recommended throwing out the disputed results of last year’s first-round presidential election and holding a new vote.
Commission President Pierre Francois Benoit said “zombie votes” and other problems meant last October’s ballot could not be considered legitimate.
Haiti has been under an interim president since February.
A run-off vote had been due in April but was postponed.
Members of the verification commission said they had audited a quarter of the 13,000 tally sheets from polling stations in their search for fraud.
A final decision on restarting the election from scratch will be made by a revamped Provisional Electoral Council, which is due to announce a new election date on Tuesday.
However, Interim President Jocelerme Privert has said Haiti cannot begin balloting again without first restoring confidence in the electoral process.
Haiti has been in political turmoil since the first round, in which Jovenel Moise came first but fell short of an overall majority.
Opposition challenger Jude Celestin accused the electoral authorities of favouring Mr Moise and threatened to pull out of the run-off vote.
Mr Privert was nominated in February to fill a power vacuum after incumbent President Michel Martelly stepped down.
Four run-off deadlines have been missed so far, on some occasions leading to violent unrest throughout the country.