OTTAWA — A search turned up additional human remains near a property linked to a self-employed Toronto landscaper who has been charged with the killings of eight people, the Toronto police said on Thursday.

“It was a bit of a surprise,” Detective Sgt. Hank Idsinga told reporters.

Earlier this year the police discovered the dismembered remains of seven men buried in planters at a home whose gardens and lawns had been maintained by the landscaper, Bruce McArthur. Mr. McArthur was charged then with eight counts of first-degree murder, although the remains of an eighth victim have yet to be discovered.

Mr. McArthur’s victims for the most part were from Toronto’s gay community; six of the men were of South Asian or Middle Eastern descent.

The serial killings have further strained relations between Toronto’s police force and gay activists, who accuse the force of failing to seriously investigate missing persons cases involving gay men that stretch back nearly a decade. Late last month the city agreed to hold an independent review of how bias affects police investigations of missing persons.