An Occupy Oakland protester who was detained during Monday’s police sweep of the movement’s encampment outside City Hall is being held without bail as federal immigration authorities determine whether to move forward with deportation proceedings.

Francisco "Pancho" Ramos Stierle is a 36-year-old Mexican immigrant who came to the United States six years ago to study astrophysics at UC Berkeley, friends told the San Francisco Chronicle. He’s been living in the country without legal status since he overstayed his student visa.

Stierle was one of 32 people detained during Monday’s sweep, but he’s the only one being held without bail at Santa Rita Jail in Dublin because he’s an undocumented immigrant.  The San Francisco Chronicle has more details:

Stierle was booked on suspicion of two misdemeanors, refusing to disperse and loitering – charges that would carry a $10,000 bail if not for the immigration hold. Alameda County sheriff’s Sgt. J.D. Nelson said his agency had no control over federal immigration holds.

Virginia Kice, a spokeswoman for U.S. Immigration and Customs Enforcement, confirmed her agency had "lodged an immigration detainer against Mr. Stierle," but declined to comment further. The detainer requires Alameda County to give immigration authorities a chance to take custody of Stierle before he is released.

Stierle was actually meditating when he was arrested on Monday. Friends say he’s a very spiritual person who "practices silence" every week. Video of his arrest shows Stierle   sitting cross-legged with his eyes closed and communicating with a police officer by writing on a notepad.

Stierle detainment is just the latest and more high profile instance in which the federal government’s controversial immigration enforcement program has come under fire. The program, Secure Communities, allows immigration officials to check the fingerprints of everyone who’s booked into local or county jails against federal immigration records. The administration has touted the program as an initiative that’s successfully led to the deportations of violent criminals. But advocates argue that many of the people who end up being deported are people convicted of non-violent offenses, like Stierle.

Several counties have tried to opt of the program, but it’s an effort that’s proved difficult. The program has become a cornerstone of the Obama administration’s immigration agenda, as record numbers of immigrants have been deported since the president took office in 2008.

Supporters have started a petition calling on Congresswoman Barbara Lee to intervene and force ICE to drop the immigration hold on Stierle immediately.

"Pancho has become an icon of peaceful protest against the unnecessary force the city of Oakland is using against the 99 percent," supporters wrote on the petition.