A Nevada judge has rejected Republican presidential candidate Donald Trump's request for records from a Las Vegas polling place that the campaign said had allowed people to vote after a deadline last week.

Mr Trump and Democrat Hillary Clinton are in a close contest for Nevada's six electoral votes in the election after a long and contentious campaign.

Nevada is one of several states that permits early voting and Las Vegas is viewed as a base of support for Mrs Clinton.

Nevada state law says voters who are in line at 8pm, when the polls close, must be allowed to cast their ballots.

Mr Trump's lawsuit, filed in a Nevada state court yesterday, said election officials violated state law because they allowed people to join the line after 8pm at a polling location at a Latino market during last week's early voting period.

Mr Trump said last month that he might not accept the outcome of the national election if he thinks it is unfair.

"We have to keep the system honest," Mr Trump said on Fox News before Eighth Judicial District Court Judge Gloria Sturman rejected his request.

The suit had asked the court to order officials to preserve various records from the Cardenas Market and to segregate ballots from the voting machines at issue.

At a court hearing in Las Vegas, a county attorney argued that election officials already preserve records.

Judge Sturman agreed, saying she did not want to issue an order that could help reveal which candidate were chosen by particular voters.

The Trump campaign also had asked for information about poll workers on duty at the market and Judge Sturman said she was concerned they might face threats for helping people vote.

"Have you watched Twitter? Do you watch any cable news shows? People can get information and harass them," the judge said.

Clinton spokesman Glen Caplin said the campaign was pleased by the ruling and described Mr Trump's suit as "a desperate response to the record turnout we're seeing in Nevada and across the country."