The Houston Chronicle on Monday announced an investigation into the work of one of its former reporters after editors said they became aware of questions about the accuracy of his stories.

The newspaper’s executive editor, Nancy Barnes, wrote that another Houston Chronicle journalist raised questions about whether Austin, Texas, reporter Mike Ward made up quotes from nonexistent people in one of his stories.

“We ask that you trust us that we’ve done everything we can to ensure what we’ve told you is fair and accurate,” Barnes said in her post. “For that reason, I want to be completely transparent with readers and tell you that we have launched an investigation into the work of one of our own reporters.”

{mosads}The newspaper’s researchers conducted a review, and could not find “a number of sources cited in Ward’s most recent reports,” Barnes said.

Ward has maintained that his reports were accurate and truthful, but has since resigned. The newspaper has hired an independent journalist to continue its investigation, Barnes wrote.

“Above all else, we need to be fair — to Ward, to our readers, and to other journalists concerned about their own reputations,” Barnes wrote.

The newspaper’s investigation comes amid heightened scrutiny of the media, which President Trump frequently derides as “fake news” and the “enemy of the people.”

The president has in recent weeks zeroed his criticism in on the use of anonymous sources. Trump has claimed on multiple occasions that anonymous sources are “made up.”

Reporters often grant anonymity to a source so they can speak freely without fear of retribution.