NBC has cut ties with Scot Chastain, a 23-year company veteran who had led affiliate marketing and planned many of the network’s spring upfront presentations to ad buyers.

A company rep’s only comment to Deadline was the following statement: “A thorough internal review was conducted. Scot Chastain is no longer with the company.” It remains unclear what conduct Chastain is accused of, or the nature of the review or the alleged misconduct.

Chastain’s most recent title was EVP marketing and development. In a 2016 corporate restructuring, he began reporting to Mark Lazarus, who took on responsibility for NBC’s local stations in addition to its sports operations.

Chastain oversaw the company’s affiliate marketing group, which develops and distributes all network marketing, sales and advertising materials for 240 owned and affiliated TV stations. On his LinkedIn page, Chastain said that in addition to those duties, “I work on existing and developing new business projects that involve the partnership between the network, stations and their respective ownership groups. I also serve as executive producer/producer of NBC’s key client presentations plus major affiliate business and marketing meetings.”

The annual upfront, held in recent years at New York’s Radio City Music Hall, is the biggest such presentation. In a 2011 YouTube video, Chastain takes viewers behind the scenes. “We’re trying to make ourselves special,” he says. “Here’s why you want to be buying NBC for the fall and into the next season. But you also want to entertain them a little bit. You want them to have a good feeling about the product we’re going to be rolling out.”

Variety first had news of Chastain’s departure.