One of two former Border Patrol agents sentenced to more than a decade in prison for shooting and wounding a suspected Mexican drug smuggler was beaten by a group of inmates last weekend, a Texas congressman confirmed to FOXNews.com.

Ignacio Ramos, who was transferred to the Yazoo City Federal Correctional Complex in Mississippi last month to begin serving his 12-year sentence for the February 2005 shooting of Osbaldo Aldrete-Davila, was placed in a special housing unit after the incident pending an investigation, according to T.J. Bonner, president of the National Border Patrol Council.

"We received verbal confirmation from the prison folks that he was assaulted and went to the infirmary and was treated for injuries," Rep. Ted Poe, R-Texas, told FOXNews.com, adding that he has requested a written report of the incident.

Another agent, Jose Compean, is serving 11 years in another facility for the same border shooting.

Prison authorities, in a statement issued Monday, said that Ramos reported to the staff on Saturday around 10:15 p.m. ET that he was assaulted and that he sustained some 'minor' bruises and abrasions, Bonner said.

Some members of Ramos' family claim the assault happened after the airing of an "America's Most Wanted" segment featuring both Ramos and Compean. They say the attack happened after Ramos fell asleep.

"Nacho was assaulted Saturday night by about five illegal immigrants who were yelling at him in Spanish, 'Maten a la migra' — which means 'kill the Border Patrol agent,'" one family member said, according to Grassfire.org, a group that has petitioned President Bush to pardon the two agents and has been working with the agents' families.

Ramos' father-in-law, Joe Loya, told FOX News that after the attack, Ramos was locked up in isolation for two days until he was given medical treatment.

Click here to watch FOX's interview with Ramos' father-in-law

Grassfire.org and Ramos' family dispute the prison report saying he suffered minor injuries. Grassfire.org in a press release says Ramos suffered "multiple and severe injuries." The release also said that a family member claims Ramos' attackers beat him with repeated blows and kicks and that he suffered wounds to his back, shoulder, arms and head.

"Our government has betrayed these agents," said Grassfire president Steve Elliott. "And now they have put these men in mortal danger. I am frightened for the lives of these two family men. This is beyond outrage, and I am calling on grassroots Americans to express their outrage directly to the White House — demanding the president pardon agents Ramos and Compean before it's too late."

Bonner said Ramos believes that he was assaulted by four or five people and that his injuries are more than 'minor."

"I believe him more than I believe the Department of Justice and its attempt to minimize this," Bonner said. "After all, this is the same Department of Justice that's tried to cover up the facts surrounding the" case, he added.

The two agents' supporters — which include a slew of lawmakers on Capital Hill — claim the Justice Department and prosecutor Johnny Sutton did not appropriately handle the case.

Ramos and Compean were found guilty by a jury of not only shooting Aldrete-Davila, but also of trying to cover up the incident. Supporters say it was wrong for Sutton to go after the border agents and not the drug dealer who was given immunity for testifying against them, and that the Justice Department has been less than forthcoming about certain facts surrounding the case.

The transcripts of the trial have not yet been released by the court.

In response to the reports of the prison assault, Rep. Duncan Hunter, R-Calif., wrote to President Bush requesting an investigation into the incident. The letter also requested that Bureau of Prisons Director Harley Lappin be discharged from his position if it's discovered that the proper precautions were not taken to protect Ramos.

"Placing these two agents in general population, especially when assuring Congress it would not happen, constitutes an enormous dereliction of duty by the Administration and the Bureau of Prisons," said the Feb. 6 letter to Bush. "The families of agents Compean and Ramos deserve an immediate response. Further, please ensure that segregation from general population occurs immediately."

On Jan. 17, Hunter requested that both agents be put in isolation for their own safety. He and others were concerned that if jailed with many of the illegal immigrants and drug runners they helped put away, the safety and well-being of Ramos and Compean would be threatened.

"The assault against agent Ramos clearly demonstrates the severe risk involved with incorporating Border Patrol agents into general prison populations," Hunter said in a statement Tuesday. "An overwhelming number of federal inmates are non U.S. citizens who have been apprehended by the Border Patrol. The danger to agents Compean and Ramos was immediately apparent and the attack against agent Ramos could have been prevented."

Rep. Tom Tancredo, R-Colo., said he spoke to several of Ramos' family members Monday night. The Ramos family wasn't aware of the situation until late Monday, when they called him to wish him well on his 38th birthday. Ramos told his family that he was attacked by five men who beat him severely for being a former law enforcement agent.

Tancredo said one of the assailants has been identified by Ramos and is now being charged with assault.

"The administration has for too long turned their back on law enforcement and left them to fend for themselves," Tancredo said. "These men have been the victims of what the Bush administration’s border enforcement policy has always been. Mr. President, pardon these men now."

Bonner said Ramos likely asked to be put in general population because when in isolation, inmates are only allowed one phone call a month. Isolated prisoners also normally are in lockdown for 23 hours a day and only allowed out for one hour.

"Why they couldn't bend that rule given the fact they have law enforcement agent in custody … you kind of go stir crazy" in isolation, Bonner said.

"I don't blame him [Ramos], I blame the folks in charge for not being reasonable about that. One phone call a month sounds like punishment to me for someone who's been acting up. But here's a guy you're putting in isolation because you need to protect him."

Poe agreed, saying that it's Ramos' choice whether he wants to be put in isolation or general population, but wherever he is, it's the job of the federal government and the prison to ensure his safety.

"It's just another example that the federal government doesn't protect Border Patrol agents on the border and doesn't protect them in prison," Poe said.

"The prison authorities, especially the federal prison system, are experts at protecting inmates from harm from other inmates ... they've been doing this for years. Why aren't they protecting Ramos?"

Ramos' attorneys are working on whether to pursue legal action in response to the assault.

"We just want him to be safe — that's our main concern right now," Loya said. "Hopefully they'll move him out of there and put him in minimum security."

The Compean family released a statement saying he is in isolation by choice. According to the Federal Bureau of Prisons, Compean is serving his sentence at the Federal Correctional Institution in Elkton, Ohio, a low-security facility housing male offenders. He was offered a chance to join general population last week, but he rejected that idea because he feared for his safety, the family said.

"This attack only reinforces why they must be kept isolated from a prison's general population," the family said in the statement.

"Being a law enforcement officer, especially knowing they are Border Patrol agents, only adds to the threat and danger they face while in prison. This is why they cannot be out of isolation. We must all take this threat seriously if we hope to see them leave prison alive."