Labour MP Dawn Butler has accused the police of "institutional racism" as she says she and her friend were pulled over for driving a "nice car”.
The former shadow equalities secretary said she was stopped by Metropolitan Police officers in Hackney, east London, on Sunday and had recorded a video of the incident.
The MP for Brent Central, in north-west London, told Sky News in an interview after the incident: "There is an institutional racism in the police, we know that, and it needs to be taken out. It is cancerous and it needs to be cut out of the police force and it's urgent.
"It is just tiring and exhausting and mentally draining.
"We're two black people in a car driving through Hackney and they thought they'll stop them."
“It makes you realise that there’s something really not right with the system,” she said.
“The fact you have two bad officers, questioning me. I can come out of my house on a nice Sunday afternoon and go wherever I want to, because it’s a free country.”
Butler, who was en route to a lunch in east London, said: “My plans were basically ruined – it’s a sunny Sunday, and you don’t get many of those.”
The Brent Central MP said she was puzzled at the idea that the police computer would – wrongly – say her friend’s car was registered out of London, and that this was sufficient reason to stop them.
The broadcaster reported that Ms Butler and her "black male friend" were pulled over while travelling in a "nice car" and that footage showed officers say they were searching the area because of "gang and knife crime".
During the video of the stop, Ms Butler tells the officers: "It is really quite irritating. It's like you cannot drive around and enjoy a Sunday afternoon whilst black because you're going to be stopped by police."
One of the officers tells her: "I appreciate everything you say and I do apologise for wasting your time."
Scotland Yard is yet to respond to a request for comment.
After the stop, former shadow home secretary Diane Abbott said: "This is so unsurprising. When will the Metropolitan Police give up on racial profiling?"
Last month Great Britain sprinter Bianca Williams and her partner Ricardo dos Santos were pulled from their car and handcuffed in front of their three-month-old son.
Nothing was found in the search and the Met referred itself to the police watchdog while the force's commissioner Dame Cressida Dick was forced to apologise for the "distress" caused.
On Saturday, Ms Butler wrote that the commissioner appeared to be "incapable" of tackling institutional racism in the police and called for her resignation.
The Independent Office for Police Conduct launched an investigation into whether officers in England and Wales racially discriminate against ethnic minority people.
The latest official statistics for stop and search showed a disparity rate of 4.3 for all black, Asian and minority ethnic people and 9.7 for black people.