Prosecutors say they will retry Bill Cosby after a judge was forced to declare a mistrial in his sexual assault case because of a deadlocked jury unable to reach a unanimous verdict.

"Our plan is to move this case forward as soon as possible," Montgomery County, Pa. district attorney Kevin Steele said in a news conference after the decision.

The district attorney's office also tweeted that a new trial date would be set and that Cosby was out on bail. The disgraced actor remains charged with three counts of aggravated indecent assault.

Bill Cosby mistrial: Reaction from defence, prosecution attorneys3:29

Jurors spent six days and more than 50 hours deliberating on whether the 79-year-old star of popular 80s and 90s sitcom The Cosby Show drugged and assaulted Canadian woman Andrea Constand, a Temple University employee, in 2004.

"We are confident that these proceedings have given a voice to the many victims who felt powerless and silenced," Constand's lawyer said in a statement on behalf of his client, thanking the jury for "their tireless efforts" and "sacrifice."

Bill Cosby

Andrea Constand walks to the courtroom during Bill Cosby's sexual assault trial at the Montgomery County Courthouse in Norristown, Pa., June 6. Cosby was charged with sexually assaulting Constand at his suburban Philadelphia estate in 2004. (Matt Rourke/Associated Press)

Camille Cosby slams proceedings

Cosby did not comment outside the courthouse. His wife of 53 years, Camille, released a seemingly hostile statement read by a member of her public relations firm.

"How do I describe the district attorney? Heinously and exploitively ambitious. How do I describe the judge? Overtly arrogant and collaborating with the district attorney. How do I describe the counsels for the accusers? Totally unethical. How do I describe general media? Blatantly vicious."

Bill Cosby

Camille Cosby, right, arrives with husband, Bill, at the Montgomery County Courthouse in Norristown, Penn., June 12. (Matt Rourke/The Associated Press)

Civil lawsuits to come

Dozens of women have come forward to say the comedian had drugged and assaulted them, but many of their cases were deemed too old to prosecute. Cosby has denied any wrongdoing. This was the only case to result in criminal charges against the actor.

'It's too early to celebrate, Mr. Cosby': Gloria Allred1:06

"If the court allows more accusers to testify next time, it might make the difference," said Gloria Allred, a civil rights lawyer representing numerous women accusing Cosby of sexual assault. "In other words, it's too early to celebrate, Mr. Cosby. Round two may be just around the corner."

Allred says she'll be in a Santa Monica, Calif., court June 27 to ask for a trial date in a civil suit against Cosby. The bar for evidence in American civil lawsuits is lower than in criminal court, where prosecutors must prove guilt beyond a reasonable doubt. In civil cases, it must only be proven that the defendant is more likely than not to be responsible for harm.

Bill Cosby

Lawyer Gloria Allred speaks with members of the media during jury deliberations in Bill Cosby's sexual assault trial June 15. Following the mistrial, she said she will continue to work on a civil suit against Cosby. (Matt Rourke/The Associated Press)

'Important for sexual assault victims'

Constand, 44, said under oath during the Pennsylvania trial that Cosby gave her three blue pills and penetrated her with his fingers as she lay "frozen" on a couch. She said she wanted it to stop but couldn't fight it.

While the prosecution took five days to present its case, which included 12 witnesses, Cosby's case called only one witness and took less than a day to lay out its defence. His lawyer claimed the encounter was consensual and Cosby did not take the stand.

During the trial, jurors heard a decade-old deposition given by Cosby as part of a lawsuit initiated by Constand in 2005.

In the deposition, the I Spy star stated that he gave Constand three half-tablets of Benadryl before the touching began.

APTOPIX Bill Cosby

Bill Cosby raises his hand as he exits the Montgomery County Courthouse after the mistrial was declared. The 79-year-old comedian and actor still faces several civil suits from women accusing him of sexual assault. (Matt Slocum/The Associated Press)

"I don't hear her say anything. And I don't feel her say anything. And so I continue and I go into the area that is somewhere between permission and rejection," he said in the 2005 testimony.

Cosby became the first African-American in 1965 to get a starring role in a weekly dramatic television series with I Spy.

His success skyrocketed with the role of the lovable American dad, Dr. Cliff Huxtable, on The Cosby Show from 1984-1992.

Bill Cosby Photo Gallery

In this Sept. 12, 1965, file photo, Bill Cosby and his wife, Camille, arrive at the TV Academy awards in Hollywood. The actor-comedian rose to fame with a starring role on the show I Spy and went on to become known as 'America's dad' for his role on The Cosby Show. (The Associated Press)

He was also the face of widespread advertising campaigns for Coca-Cola and Jell-O pudding.

After sexual assault allegations surfaced in 2014, however, his public image took a significant hit, even though many supporters remained outside the courthouse during his trial.

Prosecutors said even though the case ended without a verdict, it has been "important for sexual assault victims everywhere."

"Our job in this, as prosecutors, [is to] take on the tough cases," said Steele. "We do, and we do it because it's the right thing to do."

With files from Reuters