Republican nominee Donald Trump is refusing to pay his campaign's pollster nearly three-quarters of a million dollars, the most recent filing with the Federal Election Commission (FEC) reveals.

Trump's campaign has disputed a bill of $766,756 (£626,818) from respected Republican pollster Tony Fabrizio. The 27 October filing shows the Trump campaign disputing the bill from Fabrizio and listing it as a "contested debt".

According to the New York Times, FEC rules state that contested debt is "a bona fide disagreement between the creditor and the committee as to the existence of a debt or the amount owed by the committee."

Records show that Fabrizio was paid a separate $623,629 (£509,813) in September 2016 by the campaign. The Trump campaign has refused to provide details as to why it has decline to pay the nearly $767,000 (£627,018) to Fabrizio Lee, the pollster's Florida-based firm.

"This is an administrative issue that we're resolving internally," campaign spokesman Jason Miller told The Washington Post. Fabrizio himself did not comment on the situation.

According to the Washington Post, Fabrizio was an ally of former campaign chairman, Paul Manafort, who left the campaign in August of this year.

In turn, Trump hired pollster Kellyanne Conway as his new campaign manager, prompting questions regarding Fabrizio's future with the campaign. Reporters have also emerged that Trump and his son-in-law, Jared Kushner, rejected Fabrizio's advice.

It is not unheard-of for candidates to dispute debts they owe during their campaigns, The New York Times reported. Two former Republican candidates, Rand Paul and Ben Carson, have disputed debts in the last year.

In October, Paul disputed a $22,750 (£18,598) debt to web services firm Optimizely. In April, Carson disputed debt to Parker Air for travel expenses but later resolved the debt for a smaller amount in May.

Trump, however, is not new to allegations of unpaid debts. The Washington Post noted that Trump's real estate business has repeatedly been accused of failing vendors and contractors. In response, the GOP nominee has said he pays fairly and only withholds payment when he is dissatisfied with services provided to him.