Two key senators are pressing the Obama administration to address the problem of Islamic radicalization in American prisons.

Sen. Susan Collins has long worried that prisoners are being recruited by Islamic extremists. The Maine Republican held three hearings on the issue between 2006 and 2008, when she chaired the Homeland Security Committee and later was its ranking member.

Collins set the issue aside after the FBI during the Bush administration formed a special initiative to ensure that prisons were properly vetting Muslim clerics and the materials they bring into prisons.

But the deadly terrorist attacks in Paris and Copenhagen in January and early February renewed the senator's fears.

“We at least ought to be able to control which Islamic clerics go into the prisons and what kind of materials they bring,” Collins told the Washington Examiner Tuesday.

Collins and Sen. Barbara Mikulski, D-Md., both members of the Intelligence Committee, in late January wrote a letter to the Federal Bureau of Prisons inquiring about the protocols it’s following to try to prevent prison radicalization.

“Two of the individuals responsible for the Paris terrorist attacks, Amedy Coulibaly and Cherif Kauachi, first met at the overcrowded Fleury-Merogis prison in France,” they wrote. “This fact underscores the importance of implementing effective efforts to prevent and counter radicalization of inmates at federal prisons in the United States.”

The senators asked that the Bureau of Prisons provide them with an updated risk assessment of the threat posed by Islamic radicalization in the U.S., as well as an update regarding the “federal and state prevention and response measures to address the threat posed by this violent ideology.”

They specifically asked what steps the bureau has taken to ensure the legitimacy of Islamic-endorsing agencies regarding “suitable, qualified imams” who provide religious services to inmates. The senators also want to know whether the bureau has a plan to help reintegrate discharged inmates susceptible to radicalization when they are released.

“To be clear, our concern is not with prison inmates who convert to Islam or faithfully adhere to religious beliefs that provide them with purpose and direction,” Mikulski and Collins wrote. “Rather, our concern is with those who would take advantage of prisons as a place to indoctrinate inmates with hateful ideologies that incite adherents to commit violent acts.”

The senators gave the bureau 45 days to respond. The bureau has yet to get back to the senators but did respond to a question from the Examiner about its policies.

In an email, a spokesman for the bureau said it doesn’t believe there is a “widespread terrorist-inspired radicalization or recruiting” in federal prisons but noted that it recognizes the potential for inmates to become radicalized.

“It has been and continues to be the bureau's position that terrorist offenders in our custody must be managed through reasonable, lawful, but decisive controls to ensure they do not continue their terrorism-related activities while incarcerated, either in their interactions with other inmates, or their contacts with the public,” said Chris Burke, a spokesman for the Federal Bureau of Prisons.

The bureau, Burke said, takes part in the National Joint Terrorism Task Force, a multi-agency fusion center for terrorist threat information, and partners with the FBI in the task force’s Correctional Intelligence Initiative, formed during the Bush administration, to “detect, deter, and disrupt attempts to radicalize and recruit in all federal, state, local, territorial, tribal and privatized correctional facilities.”

The bureau also said it houses the most dangerous and sophisticated international terrorists under conditions he argued “ensure that they cannot influence others, gain reinforcing prestige or use other inmates to send or receive messages.”

When it comes to certifying Muslim clerics who provide religious services for inmates, the bureau said it has “vetting and screening protocols” but did not respond to a follow-up question from the Examiner.

There are no statistics indicating how widespread the problem is, but the risk that prisons could be breeding grounds for Islamic radicalization has long concerned government officials. In 2004, the Department of Justice inspector general’s office issued a report faulting the bureau for several deficiencies in its vetting of Islamic clergy.

The investigation began after several senators, including Chuck Schumer, D-N.Y., and Dianne Feinstein, D-Calif., pointed out that the Bureau of Prisons relied solely on two Islamic groups to endorse its Muslim chaplains, the Islamic Society of North America and the Graduate School of Islamic and Social Sciences.

Schumer also noted that the two groups allegedly are connected to terrorism and promote Wahhabism, which some consider to be an exclusionary and extreme form of Islam.

Pat Dunleavy, a former deputy inspector general for the New York State Department of Corrections and author of The Fertile Soil of Jihad, says the prison-vetting process is particularly important because in the past New York state prisons were allowing imams from the Islamic Society and other groups with questionable ties to sit on the vetting committees and participate in approving their own imams.

The groups, he said, were also sending tapes and CDs of speeches from Osama bin Laden, Muslim Brotherhood leaders and Anwar Awlaki, the now-deceased Islamic militant and prolific recruiter who operated out of Northern Virginia before returning to Yemen.

Dunleavy also warned that over the last few years smartphones have become the most frequently found item of contraband in U.S. prisons, giving the Islamic State of Iraq and Syria a direct line through its Twitter feeds and other social media recruiting.