This post was updated on Oct. 15, at 1:23 p.m.

No one connected with ESquared Hospitality is returning calls or e-mails for comment, but a source with BLT Steak confirms that chef Jon Mathieson has left the downtown steakhouse. Mathieson's last day, in fact, was Sept. 28, or more than two weeks ago.

Chef Jon Mathieson left BLT Steak last month. (BLT Steak) Will chef Jon Mathieson follow in Victor Albisu's footsteps and open his own place next? (BLT Steak)

The source, who requested anonymity because he's not allowed to speak with the media, said Mathieson left of his own accord. The restaurant's sous chefs are taking up the slack until ESquared hires a replacement for Mathieson, who joined BLT Steak in the spring of 2012 after previously working at 2941, the short-lived Michel and the equally short-lived Inox.

Mathieson had replaced chef Victor Albisu, who left BLT Steak after four years to open two of his own places, Del Campo and Taco Bamba. Del Campo just earned a spot in Post critic Tom Sietsema's Fall Dining Guide as well as a spot on Esquire critic John Mariani's list of best new restaurants in America.

It's not clear if Mathieson plans to follow Albisu's blueprint and open his own place. The chef did not return calls for comment. Mathieson was a co-owner in Inox before its demise.

BLT Steak hopes to have a new chef in place in the "near future," the source said.

A publicist for ESquared sent over the following statement on Tuesday afternoon:

"ESquared Hospitality confirms the departure of chef Mathieson. The company appreciates all the contributions he has made to BLT Steak. As he begins his new chapter, we wish him the best of luck, and our kitchen looks forward to continuing to serve the downtown D.C. community. We have identified a new chef, who will be joining BLT Steak after a training period in New York. We'll share more details as soon as we're able."