Joe Biden's 51-year-old son had an affair with 29-year-old Lunden Roberts, who fathered his secret love child in 2018.
A court-ordered paternity test revealed that Hunter was the father of Roberts' daughter, Navy Joan.
Few details are known about how the president's son met Roberts.
There are reports claiming she was a stripper in the D.C. area; however, Hunter alleged he actually met her through his daughter, Misty Biden, according to a string of leaked emails.
In the emails obtained by Daily Mail, it shows Hunter knew Roberts way before he hired her to work in his consultancy firm Rosemont Seneca in 2018.
In September 2017, a heated email conversation erupted between Hunter and the manager of his DC office building, who also houses diplomats and the Swedish embassy.
The argument occurred after the manager accused Joe's son smuggling guests -- including Roberts -- into a side door of the building after office hours.
In the exchange, Hunter alleged Roberts was "my youngest daughter's basketball mentor" who "worked out with [Hunter's youngest] Maisy and [Obama's daughter] Sasha Obama when they played in rec league together."
"I had phoned ahead to let security know that my youngest daughter's basketball mentor she worked out with Maisy and Sasha Obama when they played in rec league together," Hunter's email explained. "Maisy, my daughter continues ton [sic] pursue a NCAA Div. One team and Lunden continues to help."
He also gushed about her basketball stats and history playing the game.
Hunter went off after someone in the company emailed him and others instructing them not to bring guests through the unguarded side entrance.
The newly uncovered emails appear to contradict what Hunter said in his memoir, claiming to have "no recollection" of Roberts.