The media regulator has been empowered by government changes which are said to make the broadcaster more accountable.
Ofcom will also look into the BBC’s YouTube channel and will provide more scrutiny than ever for its television and radio output, according to plans backed by Lucy Frazer.
The culture secretary has called out the broadcaster for impartiality in its reporting - citing an example where an attack on a Gaza hospital was wrongly attributed to Israel. The missile was later shown to be from a misfiring Hamas rocket.
“This isn’t about the government. This is about impartiality and not just about politics,” Ms Frazer told Times Radio.
“Audiences are feeling impartial and the BBC is on a downward trajectory.
“It’s really important that it maintains the public’s trust. And what we’ve been hearing is that some audiences think it’s biased.”
She told Sky: “I think that on occasions it has been biased.”
Labour has said the comments prove that Ms Frazer is the "latest in a long line of Secretaries of State for Culture Wars".
The BBC has said it was consulted by Ofcom and the government before the regulations were imposed.
What is Ofcom?
The communication watchdog is independent of the government and is funded by the companies it oversees - including the BBC.
It also looks into the post, mobile signals and Wi-Fi coverage but is best known for monitoring radio and TV content.
Ofcom sets broadcasting rules and listens to complaints about content.
“We make sure you’re protected, getting a fair deal and good service,” Ofcom has said.
Last year, the most complained about television broadcast was Adjoa Andoh saying the Buckingham Palace balcony was “terribly white”.
Ofcom did not end up investigating despite 8,000 complaints.
However, there have been many times when it has stepped in - such as when Piers Morgan stormed out of an interview about Meghan Markle and when Jade Goody racially abused Shilpa Shetty on Celebrity Big Brother.
