"Boardwalk Empire" actress Paz de la Huerta publicly accused the movie producer of raping her twice in 2010. She began speaking with police about the accusation in late October.
Her lawyer, Carrie Goldberg, said that by now she expected the case would at least have gone before a grand jury, which would decide whether or not to indict Weinstein.
"We are deeply concerned about the foot-dragging in convening the grand jury," Goldberg said in an email.
Weinstein's attorneys have said he denies any claim of non-consensual sex, and that they would respond in any "appropriate legal forum, where necessary." They had no comment on Friday.
New York City authorities initially seemed poised to move quickly on the accusations. In late October, Chief of Detectives Robert Boyce said investigators found de la Huerta's account believable.
Since then, police and prosecutors have traveled to Paris to interview de la Huerta and have spoken to other witnesses multiple times, two law enforcement officials said. The officials weren't authorized to speak publicly and spoke to The Associated Press on condition of anonymity.
Prosecutors have also met with Weinstein's lawyers, Goldberg's office said.
A spokeswoman for Manhattan District Attorney Cyrus Vance Jr. she could not comment because of the ongoing investigation.
The prosecutor's office has investigated Weinstein before, only to eventually back off of filing a criminal charge. In 2015, police conducted a sting after an Italian model accused Weinstein of groping her, secretly recording Weinstein apologizing for this conduct.
Vance ultimately decided there wasn't enough proof and didn't bring a case. Following criticism over the decision earlier this year, prosecutors said police arranged the sting without their knowledge and there were other proof issues, but police pushed back saying they'd presented enough evidence.
Goldberg said she wonders why prosecutors are putting her client through so much scrutiny.
"It exacts a huge emotional toll," she said. "She has to rehash these memories and subject herself to exposure, and for what?"
She added: "We've already said we're prepared for whatever the trial may bring."
At least 75 women have come forward in the media to detail accounts of assault, harassment and inappropriate conduct by Weinstein. It's not clear how many have gone to police.
The Associated Press does not typically identify people who say they are victims of sexual assault unless they speak publicly, which de la Huerta has done.
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