A Florida man accused of murdering his girlfriend claims she accidentally choked to death while performing oral sex - and his unusual defense just might work, according to a renowned pathologist and former New York City medical examiner.

Richard Henry Patterson, 65, of Margate, now wants permission from a judge to bolster his argument by showing his penis to a jury to support his claim that Francisca Marquinez, 60, choked to death in her bedroom while performing oral sex on him on Oct. 28, 2015, the Sun Sentinel reports.

Patterson's attorney claims in a motion filed on May 1 that an expert witness and former Broward County medical examiner, Dr. Ronald Wright, will testify that Marquinez's death is consistent with being "accidentally sexually asphyxiated during oral sex," according to the motion.

"It is material and relevant," attorney Ken Padowitz wrote in the motion. "The view by the jury is essential for them to fully understand Dr. Wright's testimony and the defense in this case."

Wright, the county's chief medical examiner from 1980 to 1994, declined to comment on the unusual defense, the newspaper reports.

But Dr. Michael Baden - a former New York City medical examiner who has performed autopsies in several high-profile cases, most recently that of former NFL star Aaron Hernandez - said it's entirely possible, albeit one cause of death he hasn't come across throughout his career spanning five decades.

"There's quite a number of ways that sexual activity can lead to inadvertent deaths, but I've never heard of choking on a penis," Baden told The Post.

More common causes of death during sexual activity includes autoerotic asphyxiation - where people use devices during masturbation to enhance orgasms by partially reducing airflow to the brain - and instances where one partner compresses the neck vessels of another for increased pleasure, he said.

"It's usually the male who compresses the neck vessels of the female, with the idea that they'll have a better orgasm as the oxygen supply is diminished to the brain," Baden said. "And that can lead to death."

Baden said he's even seen cases where a woman died from receiving oral sex after a man blew air into her vagina, causing an air embolism. And although he's never heard of the oral-sex choking defense, that doesn't mean it won't work. A British man, however, tried the defense during a 2011 murder case and he's now serving a life sentence, according to the Sun Sentinel.

"That's up to the jury to decide whether to accept it or not," Baden said of Patterson's defense. "I've not seen it, that the penis alone will choke somebody to death. However, if there's obstruction, it's possible. And in order to choke to death, the penis has to obstruct the windpipe, probably down to the area of thyroid cartilage, or the Adam's apple, for a period of time."

Baden continued: "One could have no air coming in for a period of time under these circumstances and that would be possible, but I have not seen it. But it is possible."

Penis sizes vary greatly, Baden said, and accidental asphyxiation is possible due to those variations.

"Strange things can happen," he told The Post.

No date has been set for a hearing on Patterson's motion to show the jury his penis. If the judge rejects that request, Padowitz said he's considering making a mold of his client's penis, the Sun Sentinel reports.

Patterson, who has been charged with second-degree murder, called his attorney before Marquinez's body was found and she had been dead up to 24 hours when police found her body, according to arrest records cited by the newspaper.

An autopsy shows no signs of trauma, but noted that the body was already in an early stage of decomposition. The medical examiner could not reach a definitive conclusion on the cause and manner of death.

"It is rare in a murder case that the medical examiner can't say the manner of death is a homicide," Padowitz said.

Padowitz said prosecutors would be without a case if they didn't have Patterson's statements to a daughter and friend after Marquinez's death. In a text message after her death, Patterson told his daughter he "did something wrong." He later told a friend that he "choked" Marquinez.

"He said he choked her," Padowitz said. "He never said he strangled her."