"Of course, I did not molest Dylan," Allen wrote. "I loved her and hope one day she will grasp how she has been cheated out of having a loving father and exploited by a mother more interested in her own festering anger than her daughter's well-being."
Allen was investigated for the alleged molestation, but was never charged. A team of child abuse specialists from the Yale-New Haven Hospital, brought in to the case by prosecutors and police, concluded that Dylan Farrow had not been molested.
"Now it's 21 years later and Dylan has come forward with the accusations that the Yale experts investigated and found false," Allen said.
The 78-year-old director of such films as "Annie Hall," ''Bullets Over Broadway" and "Midnight in Paris" spent the majority of his letter lashing out against ex-partner Mia Farrow, calling her vindictive, spiteful and malevolent. He said he believes Mia Farrow concocted the details recounted by Dylan Farrow, and they were inspired by the song "With My Daddy in the Attic."
"Does the letter really benefit Dylan or does it simply advance her mother's shabby agenda?" Allen said. "That is to hurt me with a smear. There is even a lame attempt to do professional damage by trying to involve movie stars, which smells a lot more like Mia than Dylan."
At the time of the breakup of their 12-year relationship more than two decades ago, Mia Farrow first accused Allen of molesting Dylan Farrow. Allen has consistently denied the abuse allegation.
Their split followed the discovery of an affair between Allen and an adopted daughter of Mia Farrow, Soon-Yi Previn, when Previn was 19 or 21. (Her official date of birth is uncertain.) Allen and Previn married in 1997 and have two adopted daughters.
"I still loved (Dylan) deeply, and felt guilty that by falling in love with Soon-Yi I had put her in the position of being used as a pawn for revenge," Allen said.
In a statement made to The Hollywood Reporter late Friday, Dylan Farrow called Allen's op-ed "the latest rehash of the same legalese, distortions, and outright lies he has leveled at me for the past 20 years."
She wrote that Mia Farrow was not the one who brought criminal charges — "in fact, it was a pediatrician who reported the incident to the police based on my firsthand account." She also stated that the prosecutor found probable cause to prosecute Allen, but decided against it to protect what they called "the child victim."
The controversy comes amid accolades for Allen and his latest film. Allen received a lifetime achievement award at last month's Golden Globes ceremony, and he's up for the best original screenplay trophy at next month's Academy Awards for "Blue Jasmine," which also received acting nominations for Cate Blanchett and Sally Hawkins.
In his letter, Allen recounts several anecdotes to call Mia Farrow's integrity into question. He also addressed the claim by Mia Farrow that her ex-husband Frank Sinatra could be the father of son Ronan Farrow, not Allen.
"Even if he is not Frank's, the possibility she raises that he could be, indicates she was secretly intimate with him during our years," said Allen. "Not to mention all the money I paid for child support. Was I supporting Frank's son? Again, I want to call attention to the integrity and honesty of a person who conducts her life like that."
The 28-year-old Dylan Farrow, now married, currently lives in Florida under another name. Her letter caused an uproar, reawakening a case more than two decades after it made headlines. Some have challenged Dylan Farrow's account, most notably her 36-year-old brother, Moses Farrow. He told People magazine this week that "of course" Allen didn't molest Dylan Farrow, which she called "a betrayal."
Allen said his open letter "will be my final word on this entire matter and no one will be responding on my behalf to any further comments on it by any party."
He ended the letter by saying, "Enough people have been hurt."
Messages left by The Associated Press for Dylan Farrow, Mia Farrow and Ronan Farrow were not immediately returned.