Federal prosecutors are investigating Michael Cohen, President Trump's former personal attorney, over alleged tax fraud, The Wall Street Journal reported Tuesday.

The paper reported that authorities were looking into whether income from Cohen's taxi-medallion business was underreported in federal income tax returns. Investigators also were looking into whether bank employees provided Cohen with loans for which he did not have adequate documentation, the report said.

The Journal also reported that prosecutors have subpoenaed Jeffrey Getzel, an accountant who prepared many of Cohen's financial statements for submission to banks. Getzel also worked for taxi-medallion manager Evgeny Freidman, who is cooperating with the federal investigation.

Cohen's attorney, Lanny Davis, told Fox News that "in light of the ongoing investigation, I am unable to respond" to the report.

Prosecutors have said previously that they were investigating fraud in Cohen's business dealings, but have not publicly disclosed details. Cohen has not been charged with any crime.

Previous reports have indicated that investigators were examining whether Cohen committed bank fraud, campaign finance violations or other crimes when he paid adult film star Stormy Daniels $130,000 to keep quiet about an alleged affair she had with Trump in 2006.

Federal investigators raided Cohen's home, office and hotel room in April and seized more than four million electronic communications, recorded conversations, videos and other documents. Those items are currently under review by a court-appointed "special master" to determine what is covered by attorney-client privilege.

Lawyers for Cohen, Trump and the Trump Organization designated 12,000 documents as privileged and confidential. As of Thursday, Jones had gone through 9,000 of those files and largely split her decisions: She said 3,600 didn't qualify as privileged or highly personal.

Fox News' John Roberts and The Associated Press contributed to this report.

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