A former Defense Department (DoD) inspector-general is urging Congress to reform the Pentagon's vetting process for military chaplains, calling current procedures a potential risk to national security.

In a letter sent last month to Senate Intelligence Committee Chairwoman Dianne Feinstein and obtained by Fox News, former Inspector-General Joseph Schmitz raised concerns about the continuing role of the Islamic Society of North America (ISNA) as one of two endorsing agents for military chaplains. Schmitz pointed to ISNA's inclusion as an unindicted co-conspirator in the 2008 Holy Land Foundation terror case, saying that it "suggests that terrorist organizations can and do disguise themselves as charitable organizations."

Schmitz also noted that Louay Safi, ISNA's former endorsing agent, was an unindicted co-conspirator in the terrorism trial of Sami Al-Arian, who pleaded guilty to one count of raising funds for the Palestinian Islamic Jihad terror organization. Safi had appeared on the Defense Department's website listing ecclesiastical agents until approximately two weeks ago. He told FoxNews.com that he has "left ISNA and moved on to another career."

In his letter, Schmitz cited the case of Army Maj. Nidal Malik Hasan, currently on trial for the murders of 13 fellow soldiers at a Fort Hood, Texas military base last November. Observing that Hasan had acted as a Muslim lay leader and received training from an approved civilian religious group involved with the DoD chaplain program, Schmitz wrote that the case "demonstrates that international terrorist organizations can also try to disguise their agents as chaplains and religious lay leaders."

In 2004, Schmitz made a series of recommendations for vetting chaplain nominees which were not implemented by the Pentagon. In his Nov. 8 letter to Feinstein, he wrote that he had recommended establishing nonreligious criteria to justify removing religious organizations from the chaplaincy program. But his suggestions - which included barring groups that advocated the violent overthrow of the U.S. government and those listed on a watch list as terrorist organizations - were rejected as "legally problematic" by the Armed Forces Chaplains Board.

A DoD spokesman said that some of Schmitz's recommendations have since been implemented. For example, religious organizations can be rejected if they are under indictment and or if they appear on the State Department's list of foreign terrorist organizations.

But those changes don't go far enough, Schmitz says. "Somebody ought to challenge the DoD on precisely how it vets its chaplains as well as its chaplain 'endorsing agents' to ensure non-complicity in terrorism or criminal activities, and who, if anyone, vetted Major Nidal Hasan as a so-called 'Muslim lay leader' at Fort Hood," he wrote in his letter to Feinstein.

Read more about the military chaplain program here, here and here.