Sen. Ron Wyden (D-Ore.) speaks to reporters on Capitol Hill in Washington D.C., on May 26, 2011. Wyden said he opposes U.S. intelligence agencies’ use of “back door searches,” which allows them to gather large amounts of e-mails and phone call data to pinpoint the communications of individual Americans without a warrant. (Harry Hamburg/AP)

U.S. intelligence agencies collecting e-mail and other communications under an updated surveillance statute have violated Americans’ constitutional right to privacy at least once, a senior intelligence official acknowledged Friday.

The acknowledgment came in a letter Friday from the Office of the Director of National Intelligence to Sen. Ron Wyden (D-Ore.) declassifying several of Wyden’s statements regarding the Foreign Intelligence Surveillance Act Amendments Act of 2008.

Wyden has stated that on “at least one occasion” the Foreign Intelligence Surveillance Court held that “some collection” carried out under the revised law “was unreasonable under the Fourth Amendment.”

The FISA Amendments Act allows the government to collect, inside the United States and without a warrant, the communication of foreign targets located abroad. Americans’ communications can be picked up if they are talking to, or e-mailing, the foreign target. The communications are gathered from commercial providers under a directive from senior government officials, following court approval.

The government has “remedied” the surveillance court’s concerns, and continues to approve the collection of e-mails and calls as lawful, Kathleen Turner, director of legislative affairs for the Office of the Director of National Intelligence, said in the letter.

The disclosure of the privacy violation comes as the administration is pressing Congress to quickly reauthorize the 2008 statute, which is set to expire at year’s end. It also comes as the U.S. Supreme Court has agreed to rule on whether a group of plaintiffs has standing to bring a constitutional challenge to the law.

Most lawmakers have shown little interest in reopening a divisive debate on the issue, which was colored by the controversy over the Bush administration’s warrantless surveillance of e-mails and phone calls after the attacks of Sept. 11, 2001.

Wyden opposes the extension of the statute without greater disclosure of the updated law’s impact. In particular, he is concerned that the 2008 law allows surveillance without a warrant for each individual targeted.

In what he calls the “back door searches” loophole, Wyden says the government could gather large amounts of e-mails and phone call data, then sift through them to pinpoint the communications of individual Americans, an aide explained.

“This law clearly has had a bigger privacy impact than most people realize,’’ Wyden said Friday. “In particular, I believe that the “back door searches” loophole needs to be closed.”