Director-general George Entwistle told British lawmakers on Tuesday that it is too early to say whether sexual abuse was endemic within Britain's publicly funded national broadcaster in previous decades.
But, he said, "there's no question in my mind that what we now know happened is a very, very grave matter indeed."
Entwistle said the BBC was investigating historical allegations of sexual abuse or harassment against "between eight and 10" past and present employees, as it investigates whether Savile was at the heart of a wider pedophile ring within the corporation.
Entwistle's testimony before the Culture, Media and Sport Select Committee comes a day after the BBC aired a powerful TV documentary about the corporation's role in the expanding sex abuse scandal around Savile, who died a year ago at age 84.
Since Savile's death, scores of women and several men have come forward to say the entertainer - a longtime host of music and children's programs - abused them when they were children or teenagers. Police have identified more than 200 potential victims.
The BBC, one of the world's largest and most respected broadcasters, is under fire for failing to stop the abuse and for pulling a "Newsnight" expose on Savile from TV schedules at the last minute in December.
The sex allegations were later aired on the rival ITV network.
The head of the BBC's "Newsnight" program, Peter Rippon, has left his job pending an investigation of his decision to scrap the Savile story.
The BBC documentary on Monday night, which was watched by more than 5 million people, presented the unusual spectacle of BBC journalists grilling their own bosses about why the piece had been dropped.
Entwistle has been in the BBC's top job for just a month after years in senior news and current affairs roles.
The U.K. lawmakers' committee may also want to question his predecessor, Mark Thompson, who led the organization at the time the "Newsnight" report was yanked. Thompson was appointed chief executive of the New York Times Co. in August and is due to take up the post next month.
Few public figures have had as spectacular a fall from grace as Savile, who was knighted for his charity fundraising and praised on his death as a popular if eccentric entertainer.
Since the ITV report earlier this month, his family has removed and destroyed his gravestone, and two charities named after him have announced they will close.
It is not just the BBC that is under fire. Schools and hospitals associated with Savile's charity work stand accused of letting him abuse young people during visits, perhaps fearful that speaking out would cut off their access to his prodigious charity fundraising.
And state prosecutors have acknowledged that they investigated four abuse allegations against Savile in 2009 but did not press charges.
"There is no question that what Jimmy Savile did and the way the BBC behaved ... will raise questions of trust for us and reputation for us," Entwistle told the lawmakers. "This is a gravely serious matter and one cannot look back at it with anything other than horror."