Police say that they have located human remains in a ravine behind a Leaside property linked to alleged serial killer Bruce McArthur.

According to Det. Sgt. Hank Idsinga, investigators found the remains in a “compost pile” in a ravine on city-owned land that is located immediately behind the Mallory Crescent property.

Idsinga said that canine dogs had previously identified several areas of interest in the ravine back on May 31. He said the remains were found amid “leaves, brush and dirt” in one of the first “digging sites” that investigators looked at on Wednesday.

“We have had a lot of false positives from the canine units so we were cautiously optimistic about finding anything else and then we found the remains very quickly yesterday,” he said. We anticipated being here for weeks so when we found them that quickly it was a little bit of a surprise.”

Police previously located the dismembered remains of seven men in large planters located on the Mallory Crescent property back in February.

Idsinga said it is possible that the remains discovered on Wednesday belong to some of those victims but he said it is also possible that they belong to a person or persons who have not yet been identified.

McArthur is charged with eight counts of first-degree murder, though authorities are yet to recover the remains of one of his alleged victims – Majeed Kayhan.

“All I can say is there is some human remains we have recovered. It is possible it is more than one (person), it is possible it is part of the remains of some of the victims we have already recovered. We just don’t know yet,” Idsinga said.

Investigators have examined 100 properties

Idsinga said that investigators have examined about 100 GTA properties linked to McArthur over the last few months and conducted “several minor excavations” but did not find any other human remains.

He said that the ravine behind the Mallory Crescent property, where McArthur stored landscaping equipment, was “left as the last premise to search” partly due to logistical challenges around environmental issues, such as the removal of trees to make room for equipment.

In a somewhat atypical development, reporters were led down a steep embankment and into the ravine on Thursday, where they were briefly allowed to observe and film investigators scouring the site.

CP24’s cameras captured a number of officers taking bucket loads of soil from a partly-forested area that Idsinga identified as the compost pile.

They were then seen dumping the soil into sifting trays that had been set up on a pair of risers.

From there forensic pathologists could be seen searching through it by hand.

In an interview with CP24 later on Thursday, Idsinga said that he decided to allow reporters into the ravine so the public could see the scale of the efforts being undertaken.

“It is quite an impressive procedure that is underway there and rather than trying to explain it, I thought lets control it and get some cameras down there so people can see what we are actually up to,” he said. “We have 20 people digging down the side of the ravine, sifting through the material and I think it is something the public should see.”

Mallory Crescent property a ‘perfect location’

Idsinga said that the area that investigators are interested in is located exclusively behind the Mallory Crescent home and does not abut other properties.

He said that he "did expect" to find human remains at other properties at one point but now believes that the Mallory Crescent property and adjoining ravine are the only places among the 100 identified by police where remains were left.

McArthur had an arrangement with the owners of the Mallory Crescent property to store his landscaping tools and materials on the premises in exchange for free landscaping work.

“If you look at the location it really is the perfect location for doing something like that,” Idsinga said. “It is in the centre of the city yet completely hidden from view and there is actually an empty lot on the other side of the house so no one is peering down into the ravine and it is very hard to peer down into the backyard to see what is going on. There have been a lot of boxes checked. I think it is an ideal location to do something like this.”

Search to continue into next week

Ontario Provincial Police and Durham Regional Police are assisting with the search at Mallory Crescent, as are officials with Ontario Forensic Pathology Services.

Idsinga said that the search will continue into at least next week but could continue past that depending on what is found.

Meanwhile, the remains found Wednesday have been sent to the offices of Ontario Forensic Pathology Services for further examination.

“We are going to have some work to do identifying those remains and linking them to the McArthur investigation but I think geographically where the remains were found, we are not going to have much of an issue doing that,” Idsinga said.

McArthur was initially charged on Jan. 18 in connection with the deaths of Andrew Kinsman and Selim Esen, who had disappeared from Toronto’s gay village last summer.

He was then subsequently charged in the deaths of six other men, most of whom also had ties to the gay village.

His next court appearance is scheduled for July 23.