Davies began his career with the Birmingham Post and Mail, and joined Mirror Group Newspapers in 1961 as as a foreign correspondent and investigative reporter. He served as foreign editor of the Daily Mirror for 14 years until he was sacked by Maxwell in 1991 at the age of 52. Davies later went on to publish stories of working with Maxwell, as well as books about the British Royal Family and Northern Ireland.

Davies was first in the mass media to identify the victim of the 2007 royal blackmail plot, despite a court order preventing naming in the UK.

He was referred to as "Kite" by Private Eye because his stories were supposed to be "fliers". He has been confused with another British journalist of the same name when they were working in the same building.

Davies's second wife was the actress Janet Fielding. They divorced in 1991. As of 1993, Davies lived in Brighton, England.

In a 1992 article for the Washington Post, Christopher Hitchens describes Davies as a "polo-playing friend of Prince Charles".