The BBC is investigating up to 10 ‘serious allegations’ involving past and present employees, director general George Entwistle has said.

He gave the figure as he faced a hostile grilling from MPs about the broadcaster’s handling of claims of sexual abuse by Jimmy Savile over several decades.

He told the Commons Culture, Media And Sport select committee, when pressed on the scale of current internal investigations: “We are looking at between five and 10 serious allegations relating to activities over the whole period in question, the Savile period.”

That included claims of sexual harassment made against people still working at the BBC, he added, but he could not say how many.

Mr Entwistle said Savile’s alleged behaviour had been possible only because of a ‘broader cultural problem’ at the BBC.

And there was insufficient evidence yet to say whether or not abuse was ‘endemic’.

But he said it was important to differentiate between complaints of sexual harassment and those of criminal behaviour, such as underage sex.

Meanwhile, Dame Janet Smith said she will begin work on her inquiry into Jimmy Savile’s activities at the BBC as early as next week. The former Court of Appeal judge has been appointed to head one of the independent inquiries commissioned by the corporation.

She will look into the ‘culture and practices’ of the BBC during the years Savile was working for the corporation.