Robert Winnett, the editor selected to run The Washington Post, will not take up that position, after reports raised questions about his ties to unethical news gathering practices in Britain.

Mr. Winnett will stay at The Daily Telegraph, where he is the deputy editor, according to emails sent on Friday to employees of the London-based newspaper and to staff at The Post.

“I’m pleased to report that Rob Winnett has decided to stay with us,” read a message to Telegraph employees from the newspaper’s top editor, Chris Evans. “As you all know, he’s a talented chap and their loss is our gain.”

Will Lewis, the chief executive of The Post, confirmed the news in an email to staff.

“It is with regret that I share with you that Robert Winnett has withdrawn from the position of editor at The Washington Post,” Mr. Lewis wrote. “Rob has my greatest respect and is an incredibly talented editor and journalist.” He said that The Post would run a search to fill that role.

Mr. Winnett did not immediately respond to a call seeking comment.

Mr. Winnett earned a reputation as an unassuming newshound whose relentless pursuit of scoops earned him the nickname “Rat Boy.” But his appointment to the top editing job at The Post was jeopardized by recent reports in The New York Times and The Washington Post that detailed his connection to a private investigator who acknowledged using unethical means to obtain information.