The longtime friend and one-time boyfriend of “Real Housewives of New York City” star and entrepreneur Bethenny Frankel has been found dead of an apparent overdose at Trump Tower, a high-ranking law enforcement source tells News 4.

Dennis Shields, 51, was found dead after authorities responded to a call at the Fifth Avenue skyscraper Friday, the source says. Police officially released Shields' name Friday afternoon and confirmed they responded to a 911 call of an unconscious male inside 721 5th Avenue around 9:19 a.m.

According to DCPI, officers discovered Shields unconscious and unresponsive upon their arrival. EMS responded and pronounced him dead at the scene.

The investigation is still ongoing.

The NYC Medical Examiner will determine the cause of death. 

According to a 2016 E! News article, Shields received a master's degree in public relations, but became prominent in the banking world — serving as the CEO of LawCash, a pre-settlement funding company, since its inception in 2000. He was also a driving force in the creation of American Legal Finance Association (ALFA). Additionally, he co-founded and was chairman of YieldStreet, which is a crowdfunding company, and Esquire Bank.

Shields and Frankel have known each other for more than three decades, but didn't start dating until 2016. Phases of their on-again off-again relationship were featured in Season 10 of "The Real Housewives of New York City."

Frankel opened up about it earlier this year on "Steve Harvey," describing a shift back toward friendship. 

“I’ve been with someone on and off for years,” Frankel told Harvey in May, without identifying Shields by name. "It’s like a partnership where if we’re not being teammates and it’s not working and one man is down, then the other man is down."

"We’re trying to really kind of be good partners and be good teammates and I think relationships oddly are — and this sounds cold — but a little bit like business," she added. "If both people aren’t happy about it but slightly uncomfortable and giving up something or giving in [to] something, it doesn’t work. So both partners have to say, ‘All right, I’m in it for this.'"

In a statement to News 4, Shields' wife Jill Schwartzberg Shields said the family was devastated by the loss of their "loving father and friend."