CBC Toronto has learned from a police source that the photo of a man believed to have been killed by Bruce McArthur was just one in a cache of images of his alleged victims that the suspected serial killer kept on his computer.

The source, who spoke on condition of anonymity, also says that some 40 tips have come in to police since the photo was released, though none of the people who have come forward have said definitively that the man pictured was a relative.

The revelation comes just one day after investigators took what they called the rare step of releasing the photo in the hopes that a member of the public could identify the middle-aged bearded man.

At a news conference Monday, Det.-Sgt. Hank Idsinga said identifying the man could take weeks.

"Short of a direct family member calling and saying, 'That's so-and-so,' we have to sort through the tips and use the process of elimination," he told The Canadian Press on Tuesday. "Eventually we would pursue 'possibles' and hope that DNA or dental records would match up with found remains."

Police have said the man was dead when the picture was taken, but won't say when or how they obtained the image.

Latest remains not identified

Ahead of Monday's news conference, CBC News reported exclusively that investigators had discovered a seventh set of remains in gardening planters seized from a midtown Toronto home where 66-year-old McArthur had worked as a landscaper.

Those remains have yet to be identified. It is unknown if they are linked to any of the missing men from earlier police investigations, or if they belong to the man in the photo released Monday.

'We need to put a name to this face and bring closure to this man's loved ones,' said Idsinga at Monday's news conference. (David Donnelly/CBC)

The Mallory Crescent property has been ground zero for investigators, with at least six other sets of remains found in planters there. So far, three have been identified as belonging to Soroush Mahmudi, 50, Andrew Kinsman, 49 and Skandaraj Navaratnam, 40.

Idsinga previously told CBC News that "upwards of 20 planters" have been seized from properties across the city as part of the investigation.

Evidence pointing to causes of some deaths

On Feb. 23, McArthur was charged with first-degree murder in the death of Navaratnam. That charge followed five others in connection with the disappearances of Kinsman and Mahmudi, as well as Selim Esen, 44, Majeed Kayhan, 58, and Dean Lisowick, 47.

Idsinga has said there is evidence pointing to a cause of death in at least some of the cases, but wouldn't elaborate.

Many of the men went missing from or near Toronto's gay village.

This combination of photos shows the six men McArthur is charged with killing. Top row, from left to right: Skandaraj Navaratnam, 40, Andrew Kinsman, 49, Selim Esen, 44. Bottom row, from left to right: Dean Lisowick, Soroush Mahmudi, 50, and Majeed Kayhan, 58. (CBC/Toronto Police Service)

Navaratnam's disappearance was one of three cases included in a Toronto police task force dubbed Project Houston. In January police said another — Project Prism, set up to investigate the disappearances of Esen and Kinsman — had begun sharing information with Project Houston.

At the time, police said they had no evidence of foul play in the Project Houston investigation, which also looked into the disappearances of Kayhan and Abdulbasir Faizi, 44, whose case remains unsolved.

Segments of the LGBT community have questioned why police didn't do more to probe the cases of missing men of colour before the high-profile disappearance of Kinsman, well-known in the community for his decades of volunteer work with the Toronto HIV/AIDS Network.

McArthur is due back in court on March 14. (Bruce McArthur/Facebook)

Hundreds of cases

As CBC News reported in January, McArthur was charged with two counts of assault in 2003 after attacking a man with a metal pipe, requiring him to stay away from a section of the downtown gay village and to not be in the presence of male prostitutes. He was also ordered to provide a DNA sample.

Police have said the investigation into McArthur could last years, and that they are tracing the former landscaper's whereabouts as far back as they can go.

Dozens of officers have now been assigned to the investigation, which Idsinga has said has expanded to include "hundreds of outstanding missing person cases," old murders and some "sudden deaths."

Investigators have so far refused to discuss how McArthur's alleged victims died, but Idsinga has said police have no evidence that anyone else was involved.

McArthur is currently being held at the Toronto South Detention Centre in suburban Etobicoke. His next court hearing is set for March 14.