In the days since ROBERT F. KENNEDY JR.'s estranged wife MARY RICHARDSON committed suicide by hanging herself in the barn of her Westchester County, N.Y., estate May 16, published reports in New York have speculated whether Kennedy cheated during their marriage.

Now, in an ENQUIRER web site exclusive report, we can disclose that Kennedy not only confessed to cheating on his tragic spouse but in addition, accused her of physical abuse during their nightmare marriage!

The bombshell revelations are included in the couple's "top-secret" divorce papers.

A source who read the papers says Bobby Jr. revealed in a sworn affidavit that years of physical abuse he suffered at the hands of his wife led him to engage in extramarital affairs!

In addition, Kennedy said that even after filing for divorce, Mary — who he said was consumed by alcohol and prescription pill abuse — was "obsessed" with actress CHERYL HINES, his current lover.

According to the source, in papers filed in June 2011 with the Supreme Court of New York, County of Westchester, Kennedy further admitted Mary repeatedly attempted suicide by overdosing on pills.

Three years after their 1994 wedding, Bobby Jr. says Mary began directing physical and verbal abuse towards her husband, the source reveals.

Says the source: "Bobby said in the divorce papers her 'tantrums' were 'the daily fare in our relationship," says the source.

Kennedy swore in court documents Mary's problems escalated to physical violence, the source charges.

Bobby recalled a Ralph Lauren photo shoot for his Waterkeeper Alliance, where she ran him off the road with her car, then physically attacked him just out of sight of the film crew, the source says.

The source also notes Kennedy revealed his out-of-control wife would trap him in various rooms of their house, 'barking abuse at me for hours.'

"He said he would literally escape the house by leaping from a second story window to escape the violence. He described her as a 'trained boxer with a strong punch' and said she once hit him in the face with her fist.

"During that incident, her engagement ring crushed the tear duct in his left eye, causing permanent damage."

The court papers say the couple tried to get help, seeing psychiatrists, therapists and counselors, according to the source.

Mary sought treatment at the Caron Foundation, a facility in Pennsylvania, but it was only a few days before her 'endless cycle of rage and violence' continued," the papers revealed.

According to the source, Kennedy stated in the divorce papers that by 2001, he had "lost hope" and confessing he began "committing numerous infidelities to keep my sanity. "The affairs, however, only escalated the violence.

"He said she repeatedly threatened suicide and in front of the kids would say he was 'a demon and a sex addict.'"

The source reports Kennedy said as he began making divorce plans in 2009, Mary began attempting suicide by taking overdoses of pills: "Once in the kitchen, Bobby says, in front of the children, she cut her face and chin on a hockey skate and when police and ambulances responded to the house, she shouted, 'kill me… kill me!'

"He said she was transported to White Plains Hospital in New York for a three day evaluation."

Kennedy said he finally filed for divorce in May, 2010.

"Mary did horrible things in an attempt to stop the split," says the source.

One of the most disturbing incidents occurred May 26, 2011, when their son Aidan called his father, crying for him to come to their house, because Mary had run over the family dog, Porcia, in the driveway, the source says.

"When he got there, Bobby said Mary was intoxicated," says the source.

"When he opened the door to her room Kennedy claimed she 'leapt out of her bed and hit me with a round house punch that, had I not blocked it, would have broken my face.

"'Pointing at Aidan, she screamed, 'You told this child you didn't love me?' and hit me again, raining blows down on me as I backed down the hall. She struck me maybe 30 more times or more.'"

Adds the source: "Kennedy said Mary continued to haunt him with suicide threats, once calling 'to tell me that she needed to say goodbye to the children and she wanted to give me final instructions as to how she wanted them raised after she killed herself.'

"She said she was going to kill herself by Father's Day that year, telling Bobby, 'I'm going to give you the present you've been waiting for.'"

The source says Kennedy also stated in the June 2011 affidavit he was finally in a "'monogamous committed relationship,'" referring to his romance with Hines, who starred on the HBO comedy "Curb Your Enthusiasm", and is now on the ABC sitcom "Suburgatory."

"Without citing Cheryl by name in the document, Bobby said Mary 'is obsessed with this relationship,'" says the source. "It was a never-ending nightmare."