The "very thorough interview" lasted for eight hours, according to ESPN's Adam Schefter.
According to Pro Football Talk's Mike Florio, Hill was meeting with NFL Special Counsel for Investigations Lisa Friel in Kansas City. It is expected to be Hill's only meeting with the NFL unless he is punished, in which case he will meet with NFL Commissioner Roger Goodell in New York City as well.
Steve Vockrodt and Brooke Pryor of the Kansas City Star reported that police were called to Hill's home twice in March to check on the welfare of his three-year-old son. Hill's son reportedly suffered a broken arm, but it is unknown how it happened.
Hill shares the home with his son and his fiancee, Crystal Espinal.
No charges were brought against Hill or Espinal because of a lack of evidence, but the investigation was reopened after audio of a conversation between Hill and Espinal surfaced.
"'Why did he say daddy did it? Why did he say daddy did it?'" Espinal asked.
"'He says daddy does a lot of things,'" Hill replied.
"'A three-year-old is not going to lie about what happened to his arm,'" Espinal said. "'Daddy did it. He is terrified of you.'"
"'You need to be terrified of me, too, b---h,'" Hill said."
Espinal also said Hill hits their child when he cries: "He kept saying 'Daddy punches me,' which you do when he starts crying. What do you do? You make him open up his arms, and you punch him in the chest. Then if he gets in trouble, you get the belt out."
Hill pleaded guilty to domestic battery in 2015 stemming from a 2014 assault on Espinal while he was attending Oklahoma State. Hill was charged after choking and punching Espinal while she was pregnant with their child.
The case was later dismissed and expunged from Hill's record after he completed probation.
Hill, who is a three-time Pro Bowler and is coming off a career-high 1,479 receiving yards and 12 receiving touchdowns in 2018, agreed to stop attending offseason workouts with the Chiefs when the NFL opened its investigation.
Kansas City's training camp is set to open July 23.