Everything we know about Jeffrey Epstein's brother, Mark, who almost inherited the financier's $500 million estate

Epstein's scattered business track record has made it difficult to pin down his primary source of wealth. He headed Atelier Enterprises, Inc., a charter and leasing company, in 1984 before he began investing in New York real estate in the early 1990s.

Records reported by the Daily Beast show Mark Epstein formed his own modeling agency, Saint Model and Talent, in December 2005, but the report notes that the agency has no website or social media presence and does not appear to have ever signed a model.

His business ventures reportedly came alongside financial trouble. While plagued with recurring tax debt, Epstein tried unsuccessfully to sell his 80-foot, 3 1/2-bathoom yacht, according to The Wall Street Journal.

His wealth has been the subject of scrutiny for years, as he previously claimed to have semi-retired at age 39 and donated hundreds of thousands of dollars to charity. He has also repeatedly denied any business connections to Jeffrey, but his past deals are likely ripe for probing by federal investigators in Jeffrey's conspiracy case.

In 2002, Epstein was named Cooper's Alumnus of the Year and in 2009 he donated at least $500,000 to his alma mater, the Daily Beast reported.

That same year, he was named as chairman of its board of trustees. He later stepped down in 2015 after intense criticism of the board's decision to charge tuition at the formerly free institution.

Amid outrage over the decision, Epstein was blasted by Art In America magazine as "intimately involved in most of Cooper Union's worst decisions" during his time on the board, when he was accused of financial mismanagement.

Cooper Union Board chairman Mark Epstein surrounded by students calling for transparency #CULockIn #savecooper pic.twitter.com/pJTLbS7o

Epstein is listed on the board of directors for The Humpty Dumpty Institute, which works with the United Nations in attempts to rebuild developing countries.

The Daily Beast reported that a tax filing from the institute, where Epstein sits on the board of directors, shows Epstein loaned the international charity at least $100,000 in 2014.

The group lists Democratic representatives Maxine Waters and Adam Schiff of California and Debbie Wasserman Schultz of Florida on the congressional advisory board of the institute, the Daily Caller reported.

Epstein led a congressional delegation of Republican and Democratic representatives to an event being held in Belgium in April 2019. He previously attended a March 2019 event in the United Arab Emirates.

Epstein's real estate company, Ossa Properties, once owned around 500 renter-occupied apartments in four co-op projects in New York City, according to a 1993 New York Times report.

The Daily Beast reported that an intern for the company said it is run almost exclusively by Anthony Barrett, who records show is a former asset manager for J. Epstein. & Co and a former vice president of Ossa Properties. Epstein has denied any connection between Ossa Properties and J. Epstein. & Co., telling Crain's New York, that the information in those filings was a "mistake." But Barrett later told The Wall Street Journal that the two were indeed affiliated.

An even closer tie to Jeffrey lies in Ossa Properties' majority stake in 301 East 66th Street, a mysterious Manhattan apartment building where records show Jeffrey Epstein long housed girlfriends, associates, employees, and businesses.

The building came back under scrutiny after Jeffrey's arrest as a possible center of a trafficking operation involving young and underage models and women.

Read more: Inside the mysterious Manhattan apartment building on East 66th Street, where underage models, lawyers, and key players in Jeffrey Epstein's sex-trafficking circle all live. Ex-Israeli Prime Minister Ehud Barak is a frequent visitor.

Mark first raised eyebrows in July 2019 by offering up his Florida condo as collateral for Jeffrey's bail after his July 6 arrest.

He became another footnote in his brother's legal proceedings after Jeffrey died in jail on August 10. In a will signed just two days before Jeffrey was found dead in the Metropolitan Correctional Center, the financier described an estate worth more than $577 billion, and noted that Mark would have inherited the entire estate had Jeffrey died without a will.

But the newly signed will left nothing to Mark Epstein and said the entire estate would go to a trust that was created on August 8, the same day the will was signed.

Despite Epstein's death and the creation of a trust, the legal battles over his charges are set to continue as lawyers for his accusers have zeroed in on suing the estate.