"The neighbours to the property alerted to me that was where the prostitutes were going and it was really quite disgusting," he said.
"There was all sorts of paraphernalia, used condoms and wrappers - it really was a health hazard."
Mr Keown sent a letter to Canterbury Earthquake Recovery Authority outlining the issue.
"Two weeks ago they raided the site and demolished it," he said.
Street prostitutes have been in the northern end of Manchester St ever since the earthquakes stopped them from their traditional central city haunts.
"Look there is a great spot for them around the Kilmore St, Peterborough St and Armagh St area - there are no residents left in that area. If the girls move then the clients will follow them," he said.
Mr Keown said he had become the go-to person for residents when they had problems with sex workers.
"Residents let me know if there is a problem and then I text my contact at the police and he'll go down and check it out," he said.
The disturbances reported to him were mainly loud conversations on the street.
"These are inappropriate conversations which are happening 15 to 20 feet from children's windows," he said.
Inspector Dave Lawry said complaints regarding street prostitutes-related disturbances in residential areas north of Bealey Ave have "virtually gone".
"Following quite a concentrated police input, including beat police, complaints regarding prostitutes have virtually gone because they have returned into commercial areas to ply their trade," he said.