May 22 (Reuters) - Mexican food chain Chipotle Mexican Grill Inc said on Tuesday that federal prosecutors are conducting an investigation into possible criminal securities law violations relating to its hiring practices and statements.
The company said in a Securities and Exchange Commission filing that it was informed of the investigation on Monday by the U.S. Attorney's office for the District of Columbia.
The Denver-based company, one of the restaurant industry's top performers, fired hundreds of workers in 2010 and 2011 after audits by the U.S. Department of Homeland Security's Immigration and Customs Enforcement (ICE) arm turned up undocumented workers on payrolls in Minnesota, Virginia and Washington, D.C.
Last week, Chipotle said that the SEC had joined Homeland Security and the federal prosecutor's office for Washington, D.C., in investigating the company's compliance with immigration laws.
In its SEC filing on Tuesday, Chipotle said the U.S. attorney's office is "conducting an investigation into possible criminal securities law violations relating to our employee work authorization verification compliance and related disclosures and statements."
"We intend to continue to fully cooperate in the government's investigations," Chipotle said.
Chipotle shares were up 67 cents to $394 on Tuesday on the New York Stock Exchange.