WATERVILLE — No one is saying what happened to immigrant employees of Mexican restaurants who were apparently detained during federal raids last week.

But one thing is now known: at least 11 of those immigrants are being held for unspecified reasons at the Cumberland County Jail in Portland. A jail official on Tuesday confirmed that the immigrants have been held there since Sept. 21, the day of federal raids that resulted in the arrests of brothers Hector and Guillermo Fuentes. Hector Fuentes owns Cancun Mexican Restaurant in Waterville.

Federal officials, however, will not say why the immigrants are being held at the jail — or even acknowledge their detention there. And it remains unclear whether other immigrants taken in the raids were being held elsewhere.

The Fuentes brothers have been charged with harboring and employing illegal immigrants, but officials won’t say whether any of the detained immigrants are accused of being in the country illegally.

Chuck Jackson, spokesman for U.S. Immigration and Customs Enforcement, said Tuesday he wasn’t authorized to comment and referred questions to Assistant U.S. Attorney Donald E. Clark, who said he can’t comment on the detained immigrants, either.

“I don’t have any information on that,” Clark said. “I’m not sure there’s any public information on that.”

Clark would say it was a reasonable inference that only the Fuentes brothers have been criminally charged — and not the detained immigrants — since his office is not aware of any other charges filed in the case.

The American Civil Liberties Union of Maine is concerned with the well-being of the detained immigrants and about the alleged crimes, according to Executive Director Shenna Bellows.

“We’re definitely monitoring the situation,” Bellows said. “We want immigrants to know that if they are victims of crimes like human trafficking, they are eligible for help. The alleged crimes of these employers, in terms of immigrant workers, is definitely something we are concerned about. Immigrants need to know they have basic human rights.”

It remains unclear whether the detained immigrants have legal representation.

The Portland-based Immigrant Legal Advocacy Project, which provides immigration and related legal aid to low-income Mainers, was said to be communicating with the detained immigrants at the Cumberland County Jail. The group representative working on the case, however, did not return several requests for comment on Tuesday.

A criminal complaint filed in U.S. District Court in Maine says that between 2006 and 2009 in Maine and elsewhere, the Fuentes brothers conspired with other people to harbor aliens who entered and stayed in the U.S. illegally.

It also states that between at least 2006 and 2011, the brothers engaged in a patterns of hiring those aliens, knowing they were unauthorized to work in the U.S.

The complaint, signed by James O. Bell, special agent with federal Homeland Security, says Westbrook police officers in April 2008 pulled over Hispanic men during a routine traffic stop and the men appeared to work at Fajita Grill, claimed to be from Mexico, but could not provide any U.S. identification.

Four illegal immigrants who were interviewed during the investigation were allowed to continue living and working in the U.S. as they cooperate with authorities, and one of them was allowed to apply to become a legal resident, according to the complaint.

Armed federal agents raided the restaurants and other properties on Sept. 21. Hector and Guillermo Fuentes were released the next day after a federal magistrate judge set bail at $100,000 in property or $10,000 in cash for each man.

The charges against the Fuentes brothers relate to alleged hiring and employment practices at Cancun Mexican Restaurant in Waterville, Fajita Grill in Westbrook and Cancun Mexican Restaurant II in Biddeford.

Hector Fuentes on Tuesday declined to comment and his Waterville lawyer, Tom Nale, said he did not have any information about the Fuentes’ employees.

Rachel Talbot Ross, state director for the NAACP, said her group met recently with Westbrook police to discuss the raids and traffic stop that led to the federal investigation. Police said they were opposed to racial-profiling and they stated support for a city ordinance, modeled after one in Portland, that would specify local police do not act as federal immigration officials, Talbot Ross said.

“We agreed having this is a clear sign to the community that they do not have to fear they would be profiled in the city,” Talbot Ross said.

In postings on Cancun Mexican Restaurant’s Facebook page, the restaurant was scheduled to open at noon daily this week.

A customer recently asked on the Facebook page: “Any news on the guys from the staff? We miss them too!”

The page moderator replied on Tuesday: “We can not comment on the staff at this point; however, you can trust that they are OK.”

Scott Monroe — 861-9239

smonroe@centralmaine.com