For more than a year, 29-year-old Jafri Katagar has been a familiar sight at the intersection in front of Flinders Station Street, where he often stands with a sign over his head reading "Stop Racism Now".

But the Ugandan-born Australian was pepper-sprayed about 4.30pm on Friday after police asked him to move "following reports of a number of near misses between passing traffic and a protester standing in the middle of the street".

Videos of the incident appearing to show two officers spraying Mr Katagar have since been posted on Facebook, with supporters of Mr Katagar describing the actions of police as "outrageous".

The footage shows a male and female police officer pulling on Mr Katagar's arms in an attempt to move him off the intersection.

At first Mr Katagar pulls back, resisting their efforts to move him, before a female officer holds what appears to be a pepper spray can in front of his face.

Mr Katagar is then led off the road and into a room within Flinders Street Station.

A police spokesman later confirmed that pepper spray was deployed.

He said officers who attended the scene believed the man from Clayton was at risk of being struck by passing cars and trams, and asked him several times to move to a safer location.

"Following a number of near-misses with traffic, police advised the man he would be arrested if he did not move to a safer location," the spokesman said.

"The man still did not comply and physically resisted police when they attempted to arrest him.

"Police deployed OC spray and moved the man off the street."

About three hours after the incident Mr Katagar said he was still recovering from the "massive" pepper spray.

"It was too much. It burned my eyes, my face, my neck, my hands. I couldn't see anything. I felt like my face was burning,"

Mr Katagar said he was protesting peacefully – in his usual spot between the tram tracks outside the Young and Jackson pub - when he was asked to move by a group of police officers he had not seen before.

He said he was not blocking traffic or pedestrians.

"Most of the police, they do support me. I have police who will come give me bottles of water in summer, and they say they like what I'm doing, but there are others that are so, so, so, so bad," he said.

"It's mostly police who have seen me for the first time."

Following the incident Mr Katagar posted on Facebook that he has received police approval for his public protest.

"Before I started my campaign over a year ago I spoke to the police and got their approval to stand there, but once I started my campaign about half of the police turned against me.

"I am not breaking any law by publicly campaigning against racism. Racism is a problem in Australia affecting so many people in our society, so I will continue my fight against this racism despite the racist abuses, death threats and police brutality that I get all the time."

Mr Katagar posted a video he had previously recorded showing a police officer indicating he was permitted to carry out his protest, provided there was no safety risk.

"At the moment we are allowing you to stay given that you're not blocking any traffic," the officer said.

"If you stay right where you are here you are safe. The minute you move anywhere else and you are unsafe or are unsafe to vehicular traffic you will have to be moved."

Bystander Dilmen Ramadan filmed the incident from her Socialist Alliance stall outside Flinders Street Station.

"Week after week Jafri has been there holding up his sign and it's never been an issue. For some reason today I looked over and saw police making a fuss," Ms Ramadan said.

"It was totally unnecessary… I'm still shaken by what happened."

Mr Katagar launched his campaign against racism last year after being told by a doctor he wouldn't understand the medical system because he was from Africa and couldn't understand English.

Since his vigils began, he has described being the most-hugged man in Australia, and also the most abused.

"I came here over 10 years ago and since my time here I realised that racism is a problem and it affects us integrating within Australian society," he said.

A snap protest has been organised for outside Flinders Street station from 5pm on Saturday, with more than 400 people indicating via Facebook that they would be attending.

Protest organiser "Moo Kau" said he was appalled by the video footage of the pepper spray incident.

"Anyone who knows Jafri realises he is very nice, very peaceful and very loving," he said.

"For him to receive this treatment from Victoria Police is just abhorrent - if instead of Jafri he was Jeffrey and of Anglo appearance, I'm very sure Victoria Police would not have treated him this way."

Mr Katagar is expected to be charged on summons in relation to resisting police and obstructing traffic.