Dortmund CEO Hans-Joachim Watzke previously conceded that a "super club" had made an approach for the England teen, and now, Zorc has revealed their identity.
"A hot topic right now is Sancho and Manchester United," Zorc said on the Amazon Prime documentary "Inside Borussia Dortmund," per Sky Sports. "Both his discussions with the club and mine with the agent, a meeting did take place. Manchester United invited the agent.
"According to what I know, the agent told the club that no matter how much money they offer, we won't let him go this summer," Zorc added. "The player also has no intention of taking that step this summer."
The talented 19-year-old has been a hot commodity since making a £7-million move to Dortmund from Manchester City in 2017. Last season, he led all players in Europe's top five leagues with 14 assists while chipping in a dozen goals for Lucien Favre's lot.
On Tuesday in a Euro 2020 qualifier versus Kosovo, Sancho guided England to a frenetic 5-3 victory with a first-half brace to open his senior international goal-scoring account.
Sancho penned a contract extension with Dortmund last year that ties the London-born star to the club through 2022.