The Times cited Walnut Creek Superior Court documents in its report.
In the court documents, the alleged victim said Janikowski "did unlawfully violate (her) personal liberty" and "did willfully and unlawfully use force and violence upon (her) person" in Walnut Creek on Sept. 24, 2010, according to the Times' report. No arrest was made at the time.
"This incident occurred over a year ago, Sebastian was not arrested, we were aware of this matter and this is not news," Raiders CEO Amy Trask said in a statement.
Walnut Creek police Sgt. Lanny Edwards told The Associated Press on Saturday he had no information about the case. The District Attorney's office was closed.
Attorneys for both sides had a pre-trial conference in court Thursday, though no trial date has been set. The charges could result in a maximum of 18 months in jail and a $3,000 fine.
On Monday night, Janikowski tied an NFL record with a 63-yard field goal in Oakland's opener.
Information from The Associated Press contributed to this report.