over 19 percent, preliminary results showed in November.
But the electoral tribunal said it would review the results, after opposition candidates demanded a recount, alleging fraud.
Supporters of former President Jean-Bertrand Aristide's Fanmi Lavalas Party claimed victory for their candidate, Maryse Narcisse, while backers of leftist candidate Moise Jean-Charles also protested following the November announcement.
“There was no massive fraud in the election. There were irregularities which did not affect the electoral process,” the tribunal said. Authorities were expected to declare Moise the official winner later Tuesday.
Heavy gunfire was heard in parts of the capital on Monday. Opponents of Moise repeatedly said they would never accept the victory of the candidate of Martelly's PHTK party.
Haiti is still recovering after Category 4 Hurricane Matthew tore through the Caribbean nation, killing up to 1,000 people and leaving 1.4 million in need of humanitarian assistance.
Moise, 48, won an October 2015 first-round election that was later scrapped over fraud allegations. He is expected to take office by the constitutional deadline of February 7, 2017.
A successful banana exporter, Moise would take the reins from interim President Jocelerme Privert, who took power after Martelly left without an elected successor in February 2016.
As president, Moise would face the daunting task of reviving Haiti's economy and rebuilding a country that was still recovering from a 2010 earthquake when the hurricane hit.