CNN has fired one of its news editors after discovering she committed “multiple instances of plagiarism.”

CNNMarie-Louise Gumuchian was terminated after “an unpublished story flagged last week during our editing process led to an internal investigation that uncovered other examples in about 50 published stories,” CNN said in an editors’ note Friday. An investigation is ongoing.

Gumuchian had covered international news from CNN’s London bureau.

CNN said it has ”removed the instances of plagiarism found in her pieces. In some cases, we’ve chosen to delete an entire article.”

“Trust, integrity and simply giving credit where it’s due are among the tenets of journalism we hold dear, and we regret that we published material that did not reflect those essential standards,” CNN said. “We also believe in letting audiences know when we’ve remedied situations that threaten to compromise that trust.”

According to the Washington Post, seven articles were deleted, and most of the lifted material came from Reuters.