Roseanne Barr "crossed a line that cannot be crossed" with her racist tweet, according to ABC president Channing Dungey.



The 65-year-old actress had her eponymously titled sitcom cancelled by the television network after she made racist comments on Twitter toward Valerie Jarrett, a senior adviser to former President Barack Obama.



But the company have now claimed they had dealt with "multiple instances" of inappropriate behaviour involving Rosanne, and felt her comments were the "last straw" which they had to take action over.



Channing claimed she had had "multiple conversations" with her staff and with Rosanne about her behaviour, but claimed that despite her history, the Twitter scandal would have resulted in "some action".