Toronto police are digging up the main drainpipe in front of a property where alleged serial killer Bruce McArthur worked and stored landscaping equipment.

The digging for potential evidence started late Tuesday afternoon. The pipe is near a residence on Mallory Crescent, near Bayview and Moores avenues, in midtown neighbourhood of Leaside.

Meaghan Gray, spokesperson for Toronto police, said investigators are working with the city to search the drain.

"We are doing so to search for any evidence that may further the investigation," Gray said in an email to CBC Toronto.

Police have found the remains of at least six people in planters on the property.

"It's our final step at the property for now. Checking the drains for any evidence is fairly standard," Det.-Sgt. Hank Idsinga, the lead investigator in the case, said in an email earlier Tuesday.

McArthur, 66, is charged with five counts of first-degree murder in the deaths of five men: Selim Esen, 44, Soroush Mahmudi, 50, Dean Lisowick, either 43 or 44, Andrew Kinsman, 49, and Majeed Kayhan, 58.

Earlier Tuesday, police said they did not find additional human remains in the property's backyard. Police crews have been digging in the backyard since last Friday.

Toronto police remove equipment from 53 Mallory Cres. after excavating the backyard of the property where Bruce McArthur stored landscaping equipment. ( Ivan Arsovski/CBC)

Idsinga said crews are wrapping up their excavation at the property and the focus of forensic teams will return to the 15 planters that have been seized from various locations.

"We will have a second run at some of the properties with the dogs once the ground thaws," he said.

Idsinga confirmed more planters were removed from the property Tuesday "out of an abundance of caution."

McArthur, who was arrested by police in January, is due to appear in a Toronto courtroom via video link on Wednesday.

Five men alleged killed by Bruce McArthur are, from left to right; Selim Essen, 44, Sorush Mahmudi, 50, Dean Lisowick, either 43 or 44, Andrew Kinsman, 49, and Majeed Kayhan, 58. (Toronto Police Service/AP)

Idsinga said a second location is on hold until some tests are done at Ontario's Centre of Forensic Sciences in Toronto.

The second location is considered a potential site for excavation, according to Gray.

Gray said investigators are also reviewing outstanding missing persons cases and sorting through tips received from the public.

On Monday evening, members of more than a dozen different faiths gathered at the Metropolitan United Church to remember the five men alleged to have been killed by McArthur.