The winger looked destined to join Manchester United and still could before the October transfer deadline.
But Kehl, who is head of football operations, has doubled down on previous club statements and confirmed Sancho will be going nowhere in a fresh statement.
"It was important to get clarity on the subject," Kehl told SID.
"We know about Jadon's attractiveness, but also of his importance to us. He gives our team that little extra. We're happy that he's staying."
Dortmund were said to have set United an August 10 deadline for Sancho ahead of their pre-season camp in Switzerland.