Wal-Mart (WMT) chief administration officer and former general counsel Tom Mars will step down on March 13 after more than a decade with the company.

The world’s largest retailer, which confirmed the reports on Thursday, would not give a reason for his departure, noting the company doesn’t “comment on personnel matters.”

However, Mars, who served as Wal-Mart’s general counsel from 2002 to 2009, has been intimately involved with the company’s Mexican bribery investigation.

In 2005, he wrote an email to Wal-Mart CEO Michael Duke about the allegations, which claim that Wal-Mart executives bribed officials in Mexico to build stores near the ancient Mexican pyramids despite being in violation of the Foreign Corrupt Practices Act.

Lawmakers released a bundle of internal emails last month in an effort to intensify public pressure on Wal-Mart by claiming that its key executives may have known about the corruption as early as 2005. The emails, first leaked last year by the New York Times, show the extent that the company’s senior lawyers, including Mars, tried to brief and warn Duke of the Mexican allegations.

In one email, Mars told Duke: “You’ll want to read this. I’m available to discuss next steps.”

Wal-Mart has refuted the characterization that it lied to regulators, saying that its emails match up with prior statements. Wal-Mart says it continues to cooperate with investigators.

Separately this week, U.S. shopping center operator Kimco Realty (KIM) said it has received a subpoena from the Securities and Exchange Commission regarding the probe into Wal-Mart’s actions in Mexico. Kimco also says it is cooperating with authorities. 

Follow Jennifer Booton on Twitter at @Jbooton