The former manager of two Waterville restaurants was sentenced Tuesday in U.S. District Court in Bangor for conviction on charges that included harboring undocumented immigrants in a condemned house in Waterville that had broken pipes and no heat.

Mei Juan Zhang, 31, of Fairfield, was sentenced to 14 months in prison, followed by three years of supervised release on charges of harboring undocumented immigrants for commercial advantage and private financial gain, money laundering conspiracy and consipracy to file false employer’s tax returns.

The sentence is the third stemming from a federal investigation that culminated in the raid of several Chinese restaurants in Maine owned by Zhang’s uncle and aunt. Zhang pleaded guilty last April.

Authorities say some of the family’s restaurant managers paid their employees cash under the table, hid the money from the government and harbored undocumented immigrants.

Between 2009 and 2011, Zhang was the manager of the Grand Asian Buffet and the Super China Buffet on Kennedy Memorial Drive in Waterville, according to a statement released from the office of U.S. Attorney Thomas E. Delahanty II. The restaurants, both at 350 Kennedy Memorial Drive, have since closed.

Another member of the family, the former manager of Twin Super Buffet in Brewer, Mei Ya Zhang, pleaded guilty to the same three charges on June 5.

Both women are nieces of Zi Qian Zhang and his wife, Ai Hui Lu, of Massachusetts, who own about a dozen restaurants throughout Maine, Massachusetts and Rhode Island, according to Donald Clark, assistant U.S. attorney.

In November 2011, on the same day they raided the Waterville and Brewer restaurants, federal immigration agents raided Zhang-owned restaurants in Lewiston and Portland and the residences where their workers reportedly lived in groups, sometimes in cramped and squalid conditions.

In Waterville, the statement said, Zhang brought undocumented immigrants into Maine, where they worked 12 hours a day, six to seven days per week.

Every day, Zhang drove workers, about half of whom were undocumented, back and forth between the Super China Buffet and 7 Oak St., a house that was condemned by the city of Waterville in 2008.

At the time the three-story residence was condemned, more than a dozen Super China Buffet workers lived there with broken water pipes, serious electrical violations, shattered windows and no heat, conditions city officials called shocking.

Zhang paid the workers “under the table with cash generated illegally by the employment of undocumented aliens,” according to the statement.

It said she also “filed numerous false quarterly employment tax returns in which the undocumented aliens were not disclosed and employment taxes were not properly withheld or paid.”

Before the raid, neither Zhang nor her workers had a criminal history in Waterville, according to Police Chief Joseph Massey. Massey said he had no information that suggested they were engaged in other types of criminal activity.

Massey said that, as is typical in federal cases, the Waterville department’s role during the investigation was limited to surveillance of some of the investigation targets and providing uniformed officers during the raids.

In all, Zhang hid about $250,000 in wages and prevented about $55,000 in employment taxes from being paid.

During her sentencing Tuesday, the court also ordered Zhang to pay $54,288 to the Internal Revenue Service.

Staff members at Kon Asian Bistro, a Portland restaurant owned by Lu, said the Zhang family is not involved with the daily operation of the restaurant and that the restaurant had no immediate comment on the sentencing.

The investigation was conducted by the U.S. Immigration and Customs Enforcement’s Homeland Security Investigations, the Internal Revenue Service, Criminal Investigation, the U.S. Department of Labor, Office of Inspector General, Office of Labor Racketeering & Fraud Investigations, the statement said.

One of the Brewer restaurant workers, Walter Cruz Sanchez-Armira, was arrested during the 2011 raids and was convicted of illegal re-entry into the country after deportation.

Clark said he could not comment on whether other charges related to the case might be pending.

Matt Hongoltz-Hetling — 861-9287 [email protected] Twitter: @hh_matt