The hearing was scheduled to begin Tuesday afternoon. The grand jury, which comprises 23 people, was to review all evidence in the case and vote on whether there was enough evidence to charge Kane.
A source told The Associated Press the hearings were postponed for about two weeks.
The Buffalo News was first to report the postponement.
The reason for the delay was not immediately known.
Kane has been under investigation after a woman reportedly accused him of sexually assaulting her at his home in Hamburg, New York, last month.
Pat Brisson, Kane's agent, said Wednesday he believes Kane is innocent of any crime.
"I totally believe [Kane]," Brisson said. "He's always been honest with me. I've known him for a long time. I've been doing this a long time as a sports agent. You get to know people and get to know the character of an individual. Spending more time with Patrick over this situation, I do believe he is innocent."
Brisson said the investigation had taken a toll on Kane over the last month.
"It's been difficult, to say the least," Brisson said. "Basically when you spend more time in your house than outside and you can't really go to the rink like you have your normal life. It's been difficult. It's been hard. At the same time, I know he's looking forward to this being over with."
Information from ESPNChicago's Scott Powers and The Associated Press was used in this report.