The chair of the BBC Trust has suggested an external, "bespoke" regulator could take over the Trust's role as overseer of the corporation.
In a keynote speech at the Oxford Media Convention, Rona Fairhead said reform of the current model was the "minimum" required.
She said an external regulator would need to have "fairly strong powers" to hold the BBC to account.
The Trust is the body in charge of overseeing the BBC.
Mrs Fairhead said responsibilities for strategy, financial and operational management needed to sit with the BBC Executive, to allow them to respond to "a rapidly changing environment".
However, responsibilities for regulation and broader accountability needed "to sit at one remove", she said in her speech on Wednesday.
"That way, there should be no possibility of vagueness or uncertainty about who will be held responsible for what, when the chips are down," she added.
"The cleanest form of separation would be to transfer the Trust's responsibilities for regulation and accountability to an external regulator," she went on.
"That's an approach we want to explore further. I think it's the front-runner."
The external regulator she proposed, Mrs Fairhead continued, "would have responsibility for all matters of regulation and those matters of licence fee payer representation which require a broader, more regulatory perspective.
"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; and to prevent undue damage to the commercial market."
The BBC Board and its regulator, she said, would need to be able to act as "a protective buffer" between the government and BBC management, to ensure the organisation's independence.
There needed to be a "bespoke regulator" for the BBC, she continued, because of the "higher expectations" that audiences have for its editorial and creative standards.
"There should be a single body responsible for setting those standards for the BBC, licensing and regulating its activities, and holding it to account for the way it spends public money."
The Trust, she said, had "some concerns" about MPs' proposal for a public service broadcasting commission to monitor the corporation's performance.
The proposal was made in last month's report about the future of the BBC by the House of Commons Culture, Media and Sport Committee.
"We question [a commission's] ability to exert real authority if it were unable to set BBC service licences and editorial standards," said Mrs Fairhead.
Mrs Fairhead, former head of the Financial Times Group, replaced Lord Patten as chair of the BBC Trust last year.