ALLEN, Texas (CBSDFW.COM) – U.S. Immigration and Customs Enforcement agents in Allen wrapped up, what officials call, their largest criminal investigation at a single worksite in the last 10 years nationwide on Wednesday.

Authorities began their operation at CVE Tech Group in the Collin County city Wednesday morning in the 900 block of Enterprise Boulevard. Through the day, they detained 280 employees on administrative immigration violations for working in the U.S. illegally.

Officials said ICE will be interviewing each of the employees they detained to determine if there are any medical and/or humanitarian issues. According to ICE, most of the employees be processed for deportation.

A convoy of busses could be seen from Chopper 11 as agents loaded the detainees for processing. Agents could be seen taking the people out of the building, patting them down and putting them onto the busses.

(Credit: Chopper 11)

Katrina Berger, special agent in charge of ICE HSI Dallas, said the criminal investigation into the business began in January, and that it’s still ongoing. The investigation began after ICE received tips that the company may be knowingly hiring people who are in the U.S. illegally.

“Illegal workers… these companies need to go about it properly. They need to be using a legal workforce,” Berger said.

Officials said Wednesday’s raid was the largest at a single worksite in the last 10 years nationwide.

Investigators will be auditing the business’ I-9 forms, which all employers and employees are required to fill out upon new employment. Officials said they found numerous hiring irregularities.

“We cannot execute a search warrant for records and turn a blind eye to the illegal workers. The illegal workers are part of that criminal search warrant,” Berger said.

Friends and family of the detained workers are also left with questions of what will happen next for them. One man told CBS 11 his fiance is one of the workers in custody.

“I feel scared, really scared right now about what might happen to her,” he said.

He said she’s from Columbia on a tourist visa and admitted she’s not supposed to work in the U.S. They were scheduled to get married next month.

“I am an American citizen, so hopefully that will help her a little bit,” he said.

As the investigation continues, investigators believe the business’ managers could face charges.