Nick Robinson, the BBC's political editor, Friday apologised for directly quoting a Whitehall source who described the Woolwich killers as being "of Muslim appearance".
Robinson said he was sorry for using the phrase, which "was both liable to be misinterpreted and to cause offence", during the BBC News at Six broadcast Thursday.
The corporation received dozens of complaints after using the comment just hours after British soldier Lee Rigby, 25, was brutally murdered in the street.
Robinson Friday apologised on his BBC blog for using the phrase.
Michael Adebolajo, a 28-year-old Londoner of Nigerian descent, is one of the two suspects who hacked to death a British soldier. The vicious attack on the soldier took place Wednesday in Woolwich district, southeast London.