Jon Gruden resigned as Las Vegas Raiders' head coach Monday night, according to multiple media reports.
He reportedly stepped down in a meeting with team owner Mark Davis.
The resignation comes after further allegations of inappropriate emails surfaced Monday via reporting from the New York Times.
Rich Bisaccia likely will replace Gruden as head coach on an interim basis, according to ESPN. He has been the team's assistant head coach and special teams coordinator.
The Wall Street Journal printed a story Friday that Gruden used racist language in a 2011 email when describing the appearance of DeMaurice Smith, the executive director of the NFL Players Association. Gruden apologized but said he didn't remember writing the email.
Gruden, 58, signed a 10-year, $100 million deal to return to coaching with the Raiders in 2018.
The Raiders are off to a 3-2 start, leaving Gruden 22-31 in his second stint as the team's head coach. He was 38-26 in the regular season while coaching the then-Oakland Raiders from 1998-2001, and he posted a 57-55 regular-season mark with the Buccaneers from 2002-08, leading Tampa Bay to a Super Bowl championship after the 2002 season.
The Times reported that the NFL, in the midst of an unrelated investigation, uncovered many disparaging emails written by Gruden. He allegedly used homophobic and misogynistic terms while expressing opposition to women serving as NFL referees, the league drafting or including gay players and the player protests while the national anthem is played pregame.
Gruden also allegedly used foul terms to describe NFL commissioner Roger Goodell, including an anti-gay slur, and used a different anti-gay slur while writing about Michael Sam, the first openly gay player drafted by an NFL team. Sam was selected by the St. Louis Rams in the seventh round in 2014 but never played a regular-season game in the league.
The Raiders currently employ the only active openly gay NFL player, defensive end Carl Nassib, who has 1.5 sacks in five games this year.
Smith tweeted Monday, "The email from Jon Gruden -- and some of the reaction to it -- confirms that the fight against racism, racist tropes and intolerance is not over. This is not about an email as much as it is about a pervasive belief by some that people who look like me can be treated as less."