VANCOUVER -- A UBC master's student says he was racially profiled when he tried to enter a building at the Point Grey campus last week.

Savoy Williams, a second-year student in the Gender, Race, Sexuality and Social Justice master's program, said the incident happened when he was trying to access his supervisor's office at Buchanan Tower on June 8.

Williams says he followed the proper protocols by calling security in advance, bringing his student ID and getting a signed letter of permission from his supervisor.

But when Williams met a security guard in front of Buchanan, he says he was repeatedly questioned about the authenticity of his letter.

"He looked at it and said, 'No offense, but anyone could have made this up,' " Williams said.

The letter, which Williams provided to CTV News, explains that he had been granted access to the building's 10th floor, where the graduate student office is located, and to his supervisor's office. It goes on to say that Williams had agreed to follow sanitization protocols and wear a mask in shared spaces.

Wiliams says he also provided his student ID card and offered to show the security guard an email from his supervisor. When those didn't satisfy the guard, Williams says he offered to call the supervisor for him.

"He says, 'No, you could have someone impersonate her.’ And at that point I realized what he's doing is racially profiling me because he doesn't believe that the credentials on that letter are mine, nor does he believe that my valid student ID is mine," Williams said.

"I felt so hurt. I felt angry. And I couldn't believe that in this political climate, when you have black people protesting for the right to exist in this world, that he would put me through this."

When Williams felt defeated, he noticed a custodian who recognized him and vouched that he's a student.

"He starts interrogating her, saying, 'Are you sure? Because we've had a lot of instances of homelessness in the building with people staying. So if he's going to be in the building, are you sure you know him?' "

Williams says he felt "deeply disheartened" that he followed protocols, yet he was made to feel like he didn't belong on campus.

UBC's Graduate Student Association of the Social Justice Institute says Savoy was "unjustly targeted."

"As an Asian person, if I had that letter, I would not have been questioned," says David Ng, spokesperson for the student association. "But because Savoy is Black, he was treated differently."

Ng says this was not an isolated incident.

"I think it's very clear that there's lots of gaps in dealing with racism and further to that, education and prevention of these sorts of incident incidences. I think it's a deeper community and systemic issue at UBC that hopefully will be addressed in a real and meaningful way," he says.

One week before Williams felt he was racially profiled on campus, UBC president Santa Ono had sent a letter condemning all incidents of anti-Black and anti-Asian racism, adding there was zero tolerance for such racism and bias in the university community.

On Tuesday, Ono sent another letter saying there will be a formal external investigation into what happened to Williams.

"I have also asked for an external review of incidents, policies (and their application), practices and training within campus security to ensure that racialized members of our community are treated equally," the letter reads.

Ono says he has been meeting with members of the Black Caucus to listen and learn about their experiences with racism on campus, adding there will be further sessions with Indigenous, Asian and other marginalized groups to help form an advisory committee on systemic racism.

Savoy says no one from UBC had reached out to him before the latest letter was sent out to the university community, which was eight days after the incident.

"These feel like empty words, and I am committed and waiting for that commitment from UBC to actually do the things they are writing down and sending because it's not just me who's looking to them for accountability, it is now the entire UBC community," he said.