The Trump Organization in New York is reportedly worth one tenth of the value it previously claimed.
Donald Trump's family business had previously ranked near the top of Crain's New York Business' list of largest privately held companies.
But this year it has fallen from number three to number 40 after the President disclosed the organisation's revenue to federal regulators.
While the Trump Organization claimed $9.5bn in sales last year, Mr Trump's public filings suggest revenues of less than a tenth of that amount, between $600m and $700m.
The Crain's reporter who covered the story suggested to WNYC that he felt he had been misled following the revelation.
“It was obviously important to Donald to have his company at the top of the list and I don't know why he felt that way but the numbers that he presented are just flagrantly untrue,” Aaron Elstein said.
It comes after a YouGov poll revealed the President's signature hotel chain sat near the bottom of customer perception rankings.
Republicans were found to hold low positive opinions about Trump Hotels and Resorts, while independents and Democrats held negative views, with Democrats having the lowest perceptions.
Ethics experts have warned Mr Trump's global financial holdings could clash with his public duties