WASHINGTON – Five percent of Guantanamo Bay detainees have participated in terrorist activities since their release from the U.S. navy prison, the Pentagon said Tuesday.

An additional 9 percent are believed to have joined — or rejoined — the fight against the U.S. and its allies, according to Defense Department data released amid a simmering political battle over where to send the detainees if the prison closes in January as planned.

Constitutional scholars have long cast doubt on the Pentagon's detainee data, saying it's not proven that at least some of those who were released were even linked to terrorism in the first place.

The Pentagon maintains that all the Guantanamo detainees were captured and, in most cases, held for years, because of suspected ties to al-Qaida, the Taliban or other foreign fighter groups.

"What this tells us is, at the end of the day, there are individuals, that if released, will again return to terrorist activities," Pentagon spokesman Bryan Whitman said Tuesday.

As of April 7, the latest data available, 74 of approximately 540 detainees that have been released have since taken up the fight, or are at least suspected of doing so. The Pentagon says it has fingerprints, DNA, photos or reliable intelligence to link 27 detainees to the war since their release.

Speaking out against the United States, or participating in other anti-U.S. propaganda alone is not considered terrorist activity, the Pentagon said.