ST. LOUIS (Reuters) - A high-ranking JPMorgan Chase & Co (>> JPMorgan Chase & Co.) executive responsible for revamping the bank's anti-money laundering practices after U.S. regulators found lax controls has left in recent days, according to internal memos read to Reuters and confirmed by the bank.

Patrick Moore, a long-time JPMorgan executive who took over as global head of financial crimes investigations in May 2014, is being replaced by Peter Neilson, formerly the head of anti-money laundering compliance for JPMorgan’s consumer and community banking.

"Patrick has been a tremendous asset to our firm, and we wish him the very best with his new opportunity. We're fortunate to have a deep bench of AML talent, which includes Peter, who is an extraordinary leader in this space," Pamela Dearden, the managing director of financial crimes compliance, said in a statement provided to Reuters.

Before departing, Moore circulated a memo in which he said he was "beyond proud" of his accomplishments and said his "decision to leave was a personal one." He did not respond to a request for comment.

After taking the reins of the investigations unit, Moore tried to increase efficiency to clear a backlog of probes into possible illicit activity.

He initiated a number of changes that included pushing investigators to close more cases and shifting responsibilities traditionally performed by staff to a new automated transaction-monitoring system. Moore also oversaw the consolidation of 15 investigations offices across the country into three in Delaware, New York and Texas.

But some of Moore's decisions and his aggressive approach to implementing them created friction, according to four current and former JPMorgan employees who asked not to be identified because they were not authorized to speak with the media.

Dozens of managers from the investigations unit left on Moore's watch, either because they were unhappy or the offices in which they worked were shuttered, the employees said.

Neilson, who left an anti-money laundering executive position at Capital One (>> Capital One Financial Corp.) to join JPMorgan in 2013, will report to Dearden and Frank Pearn, chief administrative officer of the bank's global compliance department. Neilson declined comment through a JPMorgan spokeswoman.

Neilson’s appointment comes at a time when the stakes are high for JPMorgan. In 2013, regulators faulted the bank for inadequacies in its anti-money laundering program.

And the Justice Department followed with a deferred prosecution agreement over the bank's failures to catch red flags during Bernard Madoff's multibillion-dollar Ponzi scheme. The bank failed to alert U.S. authorities for more than a decade, U.S. prosecutors have said.

That agreement with prosecutors leaves the bank open to criminal prosecution until 2016 in the event of additional lapses.

(Additional reporting by Karen Freifeld in New York, Editing by Soyoung Kim and Steve Orlofsky)

By Brett Wolf

Stocks treated in this article : JPMorgan Chase & Co., Capital One Financial Corp.