The citizen-led green space, located at the corner of Saint-Urbain Street and Beaubien streets, uses private land owned by the real estate developer Olymbec.
Olymbec sent the letters to two community organizers, delivered by bailiff on June 19. The letters asked that Gorilla Park be cleared out or Olymbec would charge residents the cost of the cleanup.
"We were trying to beautify and heal a wound in the neighbourhood," said Frances Foster, one of the organizers who was served with a cease and desist letter.
"Gorilla Park brought joy to people."
Residents complied with the order and removed everything from the lot. Up until last week, the lot of land had a number of raised planter boxes.
Residents were growing pumpkins, beans, and small trees on the property. They also scattered grass seeds since the lot is currently covered in gravel.
Residents say they organized the park after Olymbec bought the land in 2013 and clear-cut the property.
They say before Olymbec bought the property, it was a green space for the neighbourhood that included mature trees and tall grass.
After the green space was cut down, the city placed the property on reserve so Olymbec could not make any further changes.
In an e-mail to CBC, Olymbec's vice-president of legal and corporate affairs Benoît Larose said the site is heavily contaminated and not fit to be occupied.
He said that the company has plans to begin decontamination, but can't begin because of the city's reserve on the land. He added that until the reserve is resolved and the decontamination is completed, no one will be allowed on the property.
Residents are hoping this will give the chance to the city to open up negotiations and buy the land for Gorilla Park.