An ex-convict says his federal prison doctor sexually assaulted him.

And the former prisoner is now suing the United States government for $1 million, claiming officials should've known better than to hire the physician, who eventually was indicted and jailed for groping inmates.

Howard Brons was an inmate at the U.S. Penitentiary in Atlanta in September 2011 when he paid a visit to then-prison physician Dr. Lewis Jackson for treatment of psoriasis on his genitalia, according to the federal civil suit.

During a follow-up visit on Oct. 12, 2011, the complaint claims Jackson asked "if there was any 'redness' when (Brons) masturbated," then the doctor began fondling Brons before performing a sex act on him, according to court records.

"Had the United States of America performed a cursory background pre-employment and-or post-employment background review of Dr. Jackson, they would have found that he was under prosecution at the time of the acts against Mr. Brons," the complaint claims, pointing to allegations that Jackson assaulted a prisoner in Washington, D.C., in 2008 and in Atlanta in 2010.

Julius Leroy Harrison attempted to sue Jackson in December 2012, claiming that in 2010 Jackson threatened to tell guards Harrison was trying to escape if he wasn't allowed to perform a sex act on Harrison.

"Who do you think they will believe? You or me?" the 2012 complaint claims Jackson said.

Harrison lost the lawsuit.

There are no records about the 2008 assault claim, but Jackson pleaded guilty in November 2012 to sexually assaulting three inmates in 2011 and 2012 in his capacity as an employee of the Atlanta penitentiary.

The victims included an inmate with the initials "H.B." who was attacked on the same date that Brons was assaulted, according to court records.

Jackson was sentenced to two years and one month in federal prison followed by two years of supervised release, according to court records.

In addition to a judgment of $1 million, Brons is seeking legal fees.