An independent watchdog group has asked the Justice Department to launch a public integrity investigation into Donald Trump, alleging that the Republican presidential nominee "vastly overstated" the value of his golf courses in the personal financial disclosures he filed with the Federal Election Commission.

In a letter sent Tuesday to Raymond Hulser, acting chief of the Justice Department's Public Integrity Section, Campaign for Accountability Executive Director Anne Weismann urged agency officials to determine whether Trump violated federal ethics laws by "knowingly making material false statements in two financial disclosure forms he submitted in July 2015 and May 2016."

In both documents, Trump gave his 16 golf courses a minimum value of $550 million, but CFA claims various other appraisals estimated the properties were worth a combined $160 million. The billionaire valued his golf club in Jupiter, Fla., at more than $50 million in his 2015 filing, but his attorney said the course was "worth no more than $5 million" in a 2014 lawsuit against a Palm Beach County appraiser.

Trump gave similar valuations on his financial disclosures to his courses in Aberdeen, Scotland and County Clare, Ireland despite having reported lower values to local authorities.

In his 2015 filing, Trump also claimed that his annual income from the Aberdeen golf course in 2014 was $4.3 million. But the course's executive vice president, Sarah Malone, told Vanity Fair earlier this month that the course "showed a net loss of $1.8 million on revenues of $4.4 million" that same year.

"Mr. Trump's financial disclosure forms appear to vastly overstate the value of these golf courses and the revenue they have generated," Weismann wrote to Hulser. He noted that in many cases, the valuations he submitted to local and state authorities reveal "that many of his courses appear to be worth tens of millions of dollars less than the valuations listed on" documents he submitted to the FEC.

"While candidates are free to engage in hyperbole on the stump, they are expected to provide honest and accurate information in their financial disclosure forms," she added in a statement about CFA's request for a public integrity investigation.

The watchdog group's findings suggest Trump may have violated the 1978 Ethics in Government Act, a law established after the Watergate scandal which mandated annual financial disclosures by federal personnel and public officials, according to Weismann.

"The applicable criminal statute … makes it a criminal offense to 'knowingly and willfully … make or use any false writing or document knowing the same to contain any materially false, fictitious, or fraudulent statement or entry,'" she wrote to Hulser.

Weismann said Trump's tendency to "play fast and loose with the truth in the political arena," does not "give him a license to deliberately overstate the value of his golf courses in forms submitted to the federal government in which accuracy is legally required."

Upon releasing his 2016 financial disclosure in late May, Trump claimed the forms contained "the largest numbers in the history" of the FEC. "Even the dishonest media thinks [they are] great!" he tweeted.

Justice Department spokesman Mark Abueg declined to comment on the request in an email to the Washington Examiner.