Donald Trump used a controversial loophole to avoid reporting hundreds of millions of dollars in taxable income in the early 1990s, according to a new report.

Because of the loophole, Trump possibly avoided paying tens of millions of dollars in federal personal income taxes, the New York Times reported Monday. The legally questionable loophole he used has since been outlawed, and at the time, Trump’s lawyers cautioned that the Internal Revenue Service would likely declare the maneuver improper, according to the Times. There’s no suggestion Trump broke the law, however.

These findings come after Trump admitted to using a $916 million loss in 1995 to avoid paying federal income taxes.

The Republican presidential nominee has yet to release his tax returns, bucking a decades-old presidential tradition and prompting suggestions that he could be “hiding something.” He has repeatedly said he will release them after the IRS completes a “routine audit,” but the audit does not prevent him from releasing the returns.

Read more in the New York Times

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Write to Katie Reilly at Katie.Reilly@time.com.