S. Epatha Merkerson, who has portrayed the tough-as-nails police lieutenant on Law & Order for 17 years, is leaving the series after its current season.

Merkerson has appeared in more than 375 episodes of the police drama, playing supervisor Lt. Anita Van Buren.

Merkerson, who captured an Emmy for her role on HBO's Lackawanna Blues, first appeared in an episode of Law & Order in its first season when George Dzundza and Chris Noth were still the lead cops.

She then joined the show as Van Buren in its fourth season in 1993.

The 57-year-old actress has been a mainstay on a series that has seen many of her co-stars come and go.

The actress told Entertainment Weekly she doubts her character, who is battling cancer, will be killed off.

"However they decide to take her out, it'll be worthy of the character. Either way, it'll be great for me because I get to act it," she told the magazine.

Merkerson's announcement may not come as much of surprise considering the venerable series has yet to get a pick up by NBC for its 21st season.