Mark Thompson said at the time he was "incredibly angry"
A senior BBC manager has left the organisation after plans to axe digital radio stations 6 Music and Asian Network were leaked to The Times.
A draft version of the BBC's strategic review was leaked 11 days ahead of planned publication on 9 March.
Director general Mark Thompson said at the time he was "incredibly angry".
The corporation said in a statement that an investigation had been "satisfactorily concluded" and that "an individual has now left the BBC".
The Putting Quality First report was published a week early as a result of the leak.
As part of the proposals, the BBC plans to close half its websites by 2013, along with teen services Switch and Blast.
Mr Thompson said he expected an extra £600m to be diverted into programme-making as a result of the changes.
Music industry figures have criticised the proposed cuts and the British Phonographic Industry (BPI) has launched a website to publicly demonstrate its support of 6 Music.
The Joy Of 6 site, which went live on Wednesday, contains tributes from artists including Elbow, The Cure, Katie Melua, Duran Duran and Kaiser Chiefs.
Union leaders have warned of strikes to fight any compulsory redundancies at the BBC as a result of the strategic review.
All of the proposed changes will have to be approved by the BBC's governing body, the BBC Trust, which will first conduct a public consultation.