"Treme" actor Michael Showers found dead Wednesday in the Mississippi River

(CBS/WWL) NEW ORLEANS - The body of Michael Showers, who played the role of police Capt. John Guidry on the HBO show "Treme," was found floating in the Mississippi River Wednesday morning, according to the New Orleans Parish Coroner's Office.

Authorities say a steamboat captain spotted Showers, 45, floating in the water between the St. Louis and Toulouse street wharfs around 11:15 a.m., local publication the Times-Picayune reports.

A spokesman for the St. Bernard Sheriff's office said Showers' girlfriend, who he lived with, had reported him missing on Tuesday, according to CBS affiliate WWL.

Authorities said Showers' girlfriend hadn't heard from him since Monday night around 11 p.m. when he apparently went into the French Quarter with a friend and did not return.

John Gagliano, chief investigator for the coroner's office estimated that the body had been in the water for about 2 days, according to the Times-Picayune.

Authorities are not saying if they think foul play is involved, WWL reports.

Wednesday night, Treme' star Wendell Pierce posted on his Twitter account: "Rest In Peace to my costar Michael Showers. 'Capt Guidry' on TREME. He will be a lasting part of our New Orleans story and television history."

Showers' acting credits also include "Breaking Bad," "The Vampire Diaries," "I Love You Phillip Morris," "Traffic" and the upcoming "Colombiana."