The "Sex and The City" actor had earlier tweeted for help in finding her brother who she said went missing from his home in Lacombe, Alberta.
Royal Canadian Mounted Police of Alberta, who had confirmed that they were actively searching for Cattrall's brother, said he was ultimately found on his property, reported CNN.
"We don't believe there is anything suspicious about the circumstances. We are not putting out any further information," said Laurel Scott, media relations officer for the RCMP Alberta.
"It is with great sadness that myself and my family announce the unexpected passing of our son and brother, Chris Cattrall," Cattrall tweeted while sharing a photo of herself and her brother.
"At this time we ask for privacy. We want to thank you all on social media for your outpouring of love and support in this trying time," she added.