The final result of the US presidential election is still unclear almost a month after polling day - and the recount in Michigan has now been thrown into chaos because of broken voting machines. As officials began a full recount in the swing state, it emerged that faulty machines mean half of all votes cast in the city of Detroit may be ineligible for recount. A third of voting precincts in Wayne County, that largest of Michigan's counties, could also be disqualified. The problems were discovered after voting clerks were unable to match the number of votes cast on the machines with the number of people who had been registered at polling stations. Officials said at least 87 of Detroit's decade-old voting machines had failed on Election Day, with many jamming when ballot papers were fed in. In 392 of the city's 662 voting precincts, the number of votes recorded on machines was not the same as the number of voters registered by polling station staff. According to Michigan state law, voting precincts where polling registers do not match with voting machines cannot be included in a recount. In that situation, the original election result will stand. The potential recount ineligibility of so many areas could hinder Hillary Clinton, who significantly outperformed Mr Trump in both Detroit and Wayne County and whose hopes of winning Michigan rest largely on uncounted ballots being found in Wayne County.