BBCA small number of BBC stars and managers "behave unacceptably" at work, and bosses often fail to tackle them, a report into the broadcaster has found.
The review, commissioned by the BBC's board in the wake of the Huw Edwards scandal, concluded there is not a widespread "toxic" culture, but that there is "a minority of people" whose bad behaviour "is not addressed".
In response, the BBC said it would introduce reforms, and its chairman Samir Shah said he would draw "a line in the sand".
He told presenters: "After today, let me state it clearly, if you think you're too big a star or too important to live by the values of this organisation, not only are you wrong, but we will find you out."
Dr Shah, who is chairman of the BBC board, said the report highlighted "some deep-seated issues", and that people who "abuse power or punch down or behave badly" have no place at the corporation.
Those people make life "not just difficult, but at times unbearable" for colleagues, he said.
While most staff are respectful, he said: "There continue to be pockets in the organisation where this is not the case. There is a minority of people whose behaviour is simply not acceptable.
"There are still places where powerful individuals on and off screen can abuse that power to make lives for their colleagues unbearable.
"The report makes several recommendations that prioritise action over procedural change, and that is exactly right. It also addresses some deep-seated issues, for example, the need to make sure everyone can feel confident and not cowed about speaking up."
The report heard from 2,500 BBC staff members and freelancers, and concluded that the corporation does not have a toxic culture overall, and that many workers feel the culture has improved in recent years.
But it found there was "a minority of people who behave unacceptably and whose behaviour is not addressed".
"These people work in both on and off-air roles, dotted across the organisation in different functions and departments. They are often in positions where power could be abused," the report said.
"Even though they are small in number, their behaviour creates large ripples which negatively impact the BBC's culture and external reputation."
The BBC has shown "inconsistent execution when it comes to dealing with poor performance and bad behaviour" over the years, it said.
Most presenters were "seen as good to work with and respectful", the report added.
But the authors heard "examples of well-known names not being held to account for poor behaviour".
The report did not publish the names of anyone accused of bad behaviour, but said some presenters' names were mentioned separately by several different employees.
"We also heard of 'untouchables' who work behind the camera or microphone," it said. "The perception was that senior management would turn an eye to poor behaviours when productions were award-winning or attracting large audiences."
BBC director general Tim Davie welcomed the "clear, practical recommendations that we are committed to implementing at pace".
The BBC's reforms include:
The corporation announced the review in the wake of revelations about Edwards, formerly its most senior news presenter, who committed offences involving child abuse images.
Separately, some BBC staff members had accused Edwards of sending them flirtatious and "pushy" private messages, and one said he was treated "like this God of news" who was "allowed to feel like he could get away with anything".
The new report comes 12 years after a previous review, carried out in the wake of the Jimmy Savile scandal, which suggested there was "a strong undercurrent of fear" at the BBC when addressing issues of bullying.
That report found some bad behaviour appeared to go unchallenged by senior managers, with certain individuals "seen as being 'untouchable' due to their perceived value to the BBC".
The past year has seen a string of allegations about BBC presenters, and questions raised about how the corporation has dealt with them.
In January, the BBC apologised to staff who felt they could not speak up with concerns about Russell Brand's behaviour because he was seen as "too influential" and they felt he "would always get his way and therefore they stayed silent".
Then in February, the BBC board apologised over "missed opportunities" to tackle "bullying and misogynistic behaviour" by former Radio 1 DJ Tim Westwood.
Jermaine Jenas, who presented The One Show and appeared on Match of the Day, was sacked last summer following complaints about workplace conduct.
Gregg Wallace stepped aside as Masterchef co-host after allegations including inappropriate sexual comments by 13 people who worked with him, which he has said are "not all true".
Two Strictly Come Dancing professionals including Giovanni Pernice did not return for last year's series, with the BBC upholding some of complaints against him, but clearing him of the most serious allegations.
