Officers from Quebec's Thérèse-De Blainville regional police force said they searched Pascal's home at 7 p.m. on Sunday.
The boxer was in Los Angeles at the time, to attend the Grammy Awards.
According to police, the 25-year-old woman said she met Jean Pascal at a bar on Saturday night, and was invited to a party at his home in Lorraine, northwest of Montreal.
The woman told police she had a non-consensual sexual interaction with someone at that party, which about a dozen people attended.
The 25 year old was taken to a hospital in Saint-Jérôme for examination, and has been questioned by police.
Pascal is expected to meet with police after he returns to Canada.
Police will not say whether Pascal is suspected of being involved in the alleged assault.
The boxer is not facing any charges.