The head of the British navy has stepped down after the Ministry of Defense launched an investigation into his relationship with a female subordinate, according to multiple U.K. media reports.

The Financial Times newspaper on Friday reported that Adm. Ben Key will be replaced on an interim basis by Vice Adm. Martin Connell.

Adm. Key was first sea lord, Britain’s equivalent of the U.S. chief of naval operations.

He resigned from the navy on Tuesday, citing “personal reasons.”

A senior Royal Navy official sounded shocked after learning of Adm. Key’s suspension. 

“Not just because he is first sea lord, but his reputation is [that of] a man of principles and morals,” the unidentified official told Britain’s Sun tabloid. “He’s a popular first sea lord.”

Adm. Key, 59, joined the Royal Navy in 1984. Among his commands was captain of the aircraft carrier Illustrious. 

• Mike Glenn can be reached at mglenn@washingtontimes.com.