Updated

The Department of Homeland Security is facing questions about a so-called "hands off" list which, according to one senator, might allow people with terror ties to enter the U.S.

Iowa Sen. Chuck Grassley, top Republican on the Senate Judiciary Committee, flagged the issue after obtaining an internal email exchange which discussed an airline passenger with apparent ties to Middle East terror groups.

The May 2012 exchange between Immigration and Customs Enforcement and Customs and Border Protection focused on whether to admit the person -- who had a scheduled flight into the U.S. and allegedly was a member of the Muslim Brotherhood and a “close associate” of Hamas, Hezbollah and the Palestinian Islamic Jihad.

The email also states the person had been the subject of advance screenings -- known as  secondary inspections -- several dozen times in the past several years but not since 2010.

A response email states that a Customs and Border Protection National Targeting Center watch commander said the person had twice sued the federal government, he’s “one of the several hands off passengers nationwide” and the DHS secretary is personally involved in the matter. The email also states the person was removed from the watchlist in December 2010.

“I am puzzled how someone could be a member of the Muslim Brotherhood, indicted as a co-conspirator in the Holy Land Foundation trail … say that the U.S. is staging car bombings in Iraq … and be afforded the luxury of a visitor visa and de-watchlisted,” the email said.

Grassley on Tuesday released the emails -- which he calls “disturbing” -- after starting an inquiry in February into the situation.

CBP Commissioner R. Gil Kerlikowske responded to Grassley’s concerns in a letter last month in which he gave only “general information” on screening procedures. However, he offered to hold a more detailed briefing on the particular case “in the appropriate setting.”

Kerlikowske also directed all questions about the terror watchlist to the Justice Department.

Among the questions raised by the senator, in a separate letter to DHS Secretary Jeh Johson, is why the individual referenced in the 2012 emails was removed from the watchlist.

Grassley spokeswoman Beth Levine said Wednesday the senator is taking a wait-and-see approach on the Obama administration’s offer to hold a briefing.

“The senator hopes for appropriate answers to his questions,” she said.

DHS did not respond to further questions about the alleged incident or the briefing.