On security camera video, dozens of party-goers can be seen pouring out of a town home on Beaufort Street near Western University.
"“We called when we were counting at least 20 people outside," says neighbour Melanie Van Schaick, who sent the video to CTV News.
"We had no idea what the volume of the house was inside at the time but when you see 20 - 30 people outside alone, you figure that had to be at least 50, so that’s when we said, 'None of this is okay.'"
Van Schaick called police, who have confirmed upwards of 150 people were in attendance.
Western University has a code of conduct policy which came to the forefront during the annual 'fake homecoming' parties on Broughdale Ave. Officials say it could come into play here.
"It is troubling to see this kind of behavior," says Jennifer Massey, VP of Student Experience at Western University.
"Should we receive names of any Western students involved, we will review all cases under the code of student conduct, follow up and apply sanctions as appropriate."
During Tuesday's media briefing, Middlesex-London's medical officer of health and London's deputy mayor both slammed those taking part in the Friday evening festivities.
"You don't have to be a public health physician to know what a terrible idea this is," says Dr. Chris Mackie, the city's medical officer of health. "This is the exactly the sort of thing that causes a whole new wave to ripple through our community. This is the sort of thing that keeps this pandemic going."
Deputy Mayor Jesse Helmer was sitting in for Ed Holder Monday and added, "That fits in the category of very, very bad idea."
"We can't be having that happen when the disease and virus is spreading pretty consistently, we cannot be doing stuff like that and people need to cut that out."
As for possible consequences, "The city is actively working with London Police Service and Western University in relation to a large party Friday evening," says Orest Katolyk, London's chief bylaw enforcement officer in a statement.
"Officers are in the process of collecting information and reviewing evidence. When the review is complete, further information will be provided."