A woman who has accused Bill Cosby of sexually assaulting her in the 1970s filed a defamation lawsuit against him Wednesday, alleging he "publicly branded" her a liar through statements made by his lawyer and publicist.

Tamara Green said in the lawsuit, filed in federal court in Springfield, that Cosby drugged and assaulted her when she was an aspiring model and singer. She said Wednesday she hoped the lawsuit would help her establish the truth about what happened.

Green first spoke publicly about the alleged attack in 2005. After she did media interviews, Cosby's lawyer and publicist made statements intended to expose her to public contempt and ridicule, she said in her lawsuit.

The attorney, Walter M. Phillips Jr., said he represented Cosby in 2005 but no longer does, and he declined to comment further. Messages left for the publicist, David Brokaw, weren't immediately returned.

Cosby, who has a home in Shelburne Falls, is the lawsuit's only defendant. He has never been charged in connection with any sexual assault allegations.

In 2005, he settled a civil case filed by Andrea Constand, a former employee at Temple University in Philadelphia. Green was one of a dozen women prepared to testify in Constand's lawsuit that Cosby sexually assaulted them.

Cosby, through his representatives, has denied renewed allegations by women alleging decades-old assaults.

Green's attorney, Joseph Cammarata, held a news conference in Washington, D.C., on Wednesday, and Green appeared via video. Green said it was important for her to prove she's not lying because "there's always been a slight doubt in everyone's mind as to the veracity of any of the allegations."

"So this will give me and other women ... a chance to go to a forum where we will speak our stories and tell our truth," she said. "And the most important thing is that Bill Cosby will be required to appear in court and to speak, and he will finally be heard."

Cammarata said the criminal statute of limitations has expired for Green and Cosby's other accusers. He said he has another client who likely will join the lawsuit, which seeks unspecified compensatory and punitive damages.

Los Angeles attorney Martin Singer, who has represented Cosby in the recent round of allegations, said of Green's lawsuit: "We are very confident that we will prevail in this proceeding and we will pursue claims against the attorneys who filed this action."

Green's lawsuit says that after she met Cosby through a mutual friend in 1969 or 1970 he asked for her to raise money from investors for a club he wanted to open.

She said she called Cosby one day in the early 1970s to tell him she wasn't feeling well. Her lawsuit says Cosby then invited her to meet him for lunch at a Los Angeles restaurant.

Green said that during lunch Cosby offered her some red and gray pills, telling her they were over-the-counter cold medicine. Green took the pills and began feeling weak and dizzy, according to the lawsuit. Cosby drugged Green "into this altered state, in order to facilitate his later sexual assault," the lawsuit states.

Green said Cosby drove her home. Once inside her apartment, he undressed both of them, then "digitally penetrated her," her lawsuit states.

Green said she repeatedly told Cosby, "you're going to have to kill me" in an attempt to stop him but he didn't stop until she upended a table lamp.

Green, who became a lawyer, said during an interview with NBC's "Today" show in 2005 that Cosby had petted, kissed and fondled her but didn't say he raped her. She gave a similar description in an interview with MailOnline in November. But in a November interview with the Washington Post, she said Cosby digitally penetrated her after petting and groping her.

Her lawsuit alleges that after she appeared on "Today" and did an interview with The Philadelphia Inquirer in 2005, Cosby, through Phillips, responded by saying he didn't know her, her allegations were "false" and the alleged attack "did not happen."

"Thus by innuendo and effect, Defendant Cosby publicly branded Plaintiff Green a liar," the lawsuit states.