The actress was present when Bieber confronted and allegedly struck a photographer as the couple were leaving a cinema over the weekend.
Bieber has since become suspected of misdemeanor battery, although he apparently has not yet been interviewed by police.
A Calabasas, CA police spokesperson has now confirmed that authorities wish to speak with Gomez, but clarified that the case has not yet been turned over to prosecutors.
Sgt Michael Holland told Radar Online: "The case hasn't been referred to the Los Angeles County District Attorney's office because the investigation is only just beginning. The only statement that has been given is from the alleged victim and other eyewitnesses, including Mr. Bieber's girlfriend, Selena Gomez, need to be interviewed.
"At some point very soon, I anticipate that detectives will formally reach out to Justin Bieber for a request for an interview, although he isn't under any obligation to do so and neither is his girlfriend."
Bieber is currently out of the country, having flown to Norway for an apparent series of "secret" concerts in Europe.
Gomez's only public statement on her boyfriend's reported clash with a paparazzo was a message to her fans on Facebook in the immediate aftermath of the incident.
"THANKS YOU SO MUCH to my fans for always protecting me and being there for me. I can't thank you guys enough. I'm sorry I had to rush out. Love you guys," Gomez wrote on Sunday (May 27).
Bieber has not publicly responded to the Calabasas police department's request to question him.
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