Police were called to the Scarborough, Ontario, home of Chun Qi Jiang around 10:45 a.m. Sunday and found his mother dead, The Toronto Star reported.
Police said Jiang's mother's death did not appear to be suspicious.
On Aug. 26, Jiang, 40, was charged with second-degree murder in the death of his estranged girlfriend, Guang Hua Liu.
Parts of Liu's body were found in the Credit River in Mississauga and in Highland Creek in Toronto. Liu, 41, was last seen alive Aug. 10 and was reported missing the next day.
Jiang, a Canadian citizen who emigrated from China 10 years ago, has been in custody since his first court appearance two weeks ago.