BBC director general Mark Thompson has said the corporation pays its stars large salaries to fend off bids from rivals.

His statement follows press reports detailing how much radio presenters earn – including £630,000 for Radio 1's Chris Moyles and £540,000 for Chris Evans on Radio 2.

The figures provoked some questioning, but Thompson said commercial rivals were offering the employees "far, far higher rates than they are currently getting". He also pointed out that salaries in the corporation were rising 2 per cent a year compared with 2.7 per cent for the media in general.

A BBC investigation into how the salaries were leaked is underway, the corporation having said it was "concerned" about the release.