A US federal judge refused on Thursday President Donald Trump's effort to block the release of his financial records subpoenaed by a New York grand jury in a case focused on hush money payments and possibly bank fraud.

Judge Victor Marrero rejected Trump's argument that the investigating jury's demand for eight years of tax records from his accountants Mazars USA was too broad and constituted political harassment.

The Manhattan federal court judge said Trump's reasoning amounted to a "back door" attempt to invoke absolute immunity after the president's lawyers' were denied by the US Supreme Court in July.

For three years Trump has been successful at fending off Congressional demands for his records in probes targeting his financial ties to Russians, his possible record of tax avoidance and other issues involving his real estate business.

However, New York federal district attorney Cyrus Vance opened last year an investigation into Trump's payments in 2016 to allegedly buy the silence of two women who claimed to have had affairs with him.

Court documents have suggested that Vance's grand jury probe has now expanded to possible banking and insurance fraud.

Marrero suggested that Trump's most recent arguments were simply an effort to delay the proceedings, potentially running out the clock on time limits for prosecutions, and risking the loss of witnesses.

Still, the ruling was not likely to force the release of Trump's records before the November presidential election.

Trump can appeal the ruling, a process that could easily be stretched out over the next three months.

At the White House, the president said the case is a "fishing expedition" and claimed that the Supreme Court said he did not have to comply in that case.

"So we'll probably end up back in the Supreme Court. But this is just a continuation of the most hideous witch hunt in the history of our country," he told reporters.