Senior police official John Yates was long seen as thoroughly reliable and was given the most sensitive cases to handle.
The assistant commissioner in the Metropolitan Police Service resigned Monday amid questions about why he didn't reopen inquiries into eavesdropping on voice mail messages by tabloid newspaper, the News of the World.
Once regarded as a "safe pair of hands," the 52-year-old endured prolonged, hostile questions last week from a parliamentary committee over his one-day review in 2009 which concluded that there was no evidence to justify a further investigation.
Yates is only the latest casualty of the spiraling scandal. His boss resigned Sunday, and 10 people have been arrested.