BBC Trust boss Rona Fairhead has proposed setting up an external regulator with "strong powers" to oversee the corporation.
Ms Fairhead, who replaced Lord Patten in the role last year, said oversight could not be left to the Government if the BBC "is to remain independent" and that a "bespoke regulator" was needed for the corporation.
She told an audience at the Oxford Media Convention that reform of the current model, which included being "more specific" about its responsibilities, was the "minimum" required.
She said: "But the cleanest form of separation would be to transfer the Trust's responsibilities for regulation and accountability to an external regulator. And that's an approach we want to explore further. I think it's the front-runner."
She said the idea "needs to be tested thoroughly" but it would "provide maximum clarity about who is accountable".
Ms Fairhead added: "But for it to work, the regulator would need to have fairly strong powers and levers – to hold the BBC to its public purposes and to the standards that audiences expect."
She said the BBC needed a bespoke regulator because of "the higher expectations" audiences have of it.