A number of Arabic and Pashtu interpreters at the terror-war detention center at Guantanamo Bay are under active investigation for omitting valuable intelligence from their translations of detainee interrogations, among other security breaches. This could taint some of the evidence at the “9/11 trial” in New York and proceedings against other detainees.

Remarkably, the Pentagon never cleaned up the “mole infestation” at its highest-security facility after the FBI busted a Muslim spy ring at Gitmo in 2003.

The 2003 probe involved at least two Arabic interpreters with high-level security clearance. Senior Airman Ahmad al-Halabi, a Syrian native, and former Army linguist Ahmed Mehalba, an Egyptian native, were later convicted of stealing or mishandling classified documents.

Six years later comes a new problem with Muslim personnel who have virtually unfettered access to detainees and intelligence at Gitmo. Professional military security and intelligence officials at Gitmo did the preliminary probe, then prepared a classified summary and are now briefing top officials and members of Congress in Washington. An active FBI criminal probe is also under way.

The possible new spy ring involves several Arabic linguists, some also Egyptian and Syrian immigrants. They’re suspected of, among other things:

* Omitting valuable intelligence from their translations of interrogations.

* Slipping notes to detainees inside copies of the Koran.

* Coaching detainees to make allegations of abuse against interrogators.

* Meeting with suspects on the terror watchlist while back in the United States.

Officials say some of the suspected “dirty” linguists — who met privately in a locked mosque at Gitmo — have had access to 9/11 mastermind Khalid Sheik Mohammed and other high-value al Qaeda detainees.

“Three years of investigations have revealed the presence of pro-jihad/anti-Western activities among the civilian-contractor and military-linguist population serving Joint Task Force Guantanamo,” states a copy of a classified Gitmo briefing, prepared in May for the FBI, CIA and Congress’ intelligence committees.

The report explains that dirty Arabic linguists have gathered classified data involving detainees, interrogations and security operations in an effort to “disrupt” Gitmo operations and US “intelligence-collection capabilities.”

It goes on to specifically finger the Muslim Brotherhood, a terrorist organization. The US operations and front groups of the Egypt-based brotherhood are the subject of my recently released book, “Muslim Mafia,” which first revealed the contents of the secret Gitmo report.

“These actions are deliberate, carefully planned, global, and to the benefit of the detainees and multiple terrorist organizations, to include al Qaeda and Muslim Brotherhood,” the briefing states.

How did this happen at the highest security facility in the world? In the wake of the Abu Ghraib scandal, US officials went from waterboarding terrorists to handing them prayer rugs and Korans, while calling them to prayer five times a day. Pentagon political correctness dictated turning a blind eye to any questions of loyalty among Muslim linguists and chaplains.

Compromised interrogations could affect releases and trials — and the problems go much further.

At least one in seven former Gitmo detainees has returned to terrorism or militant activity. Some recidivists had met with the suspect Muslim translators. Others were privately counseled by Muslim chaplains and lay leaders also under investigation for security breaches.

If they fed intelligence to these repatriated detainees, then al Qaeda and the Taliban may know what we know about them and adjust accordingly.

Prisoners released from Gitmo are allowed to keep their Korans — and it’s camp policy not to search the holy books. Non-Muslim personnel can’t even touch them. There’s no telling what military secrets have been compromised.

Also in question is just how far the enemy has penetrated our critical foreign-language program — not just at Gitmo, but across the entire national security and intelligence complex. Many Arabic linguists are contractors who rotate in and out of the federal security agencies leading the War on Terror.

To prevent future betrayal, the government must reevaluate its security-clearance and hiring procedures for contract and military linguists. Post-hiring, it must institute periodic security interviews, polygraph exams and database-access audits for each translator.

More immediately, it must review key translations on the shelf for accuracy, using trustworthy translators — and subject new translations to spot-checking in a stringent quality-assurance program.

The translation of intelligence against our enemy — evidence that will now be tested in civilian court — can no longer be blindly entrusted to individuals with possibly divided loyalties.

Paul Sperry, a Hoover Institution media fellow, is author of “Infiltration” and the new book “Muslim Mafia.” Sperry@SperryFiles.com