Angry viewers have led a boycott of Seven's Sunday Night around the hashtag #NotMyAustralia, over a segment about African gangs "wreaking havoc" in Victoria.

The Sunday Night story was described as "racist propaganda" by online commenters, with some even shaming corporate advertisers who aired commercials during the segment.

The episode focused on Elaine French, an accountant at a Melbourne jewellery store who claimed she'd been left traumatised after being robbed twice by "armed African criminals".

"Barely a week goes by when they're not in the news. African gangs running riot, terrorising, robbing, wreaking havoc," went presenter Alex Cullen's fiery opening, blaming "political correctness" for police reluctance to "admit there's a problem".