Richard Henry Patterson, 65, claims his fiancee Francisca Marquinez (pictured) accidentally choked to death while performing oral sex

Richard Henry Patterson, 65, is accused of strangling Francisca Marquinez to death in Florida in 2015. He has not denied choking her to death but disputes the manner in which it happened.

Patterson’s lawyer Ken Padowitz has asked the presiding judge allow the jury to view his client’s penis to prove his claim Ms Marquinez, 60, died accidentally, choking while she performed oral sex.

“Dr. (Ronald) Wright, an expert witness and former Broward County medical examiner, will testify that … her death is consistent with being accidentally sexually asphyxiated during oral sex,” Mr Padowitz wrote in a motion submitted to court, the Sun Sentinel reported.

“It is material and relevant,” lawyer Ken Padowitz wrote in the motion. “The view by the jury is essential for them to fully understand Dr. Wright’s testimony and the defence in this case.”

Mr Padowitz has requested that the disrobing take place in a private room with only the jury, judge, defendant, prosecutors and defence team present.

“My client is innocent and we are confident when the jury hears the evidence and the scientific evidence in this case, they are going to come back with a verdict of not guilty,” he told the Daily News.

Richard Henry Patterson, 65, and the girlfriend he’s accused of murdering, Francisca Marquinez, 60, in happier times.Source:Facebook

The “rough sex defence” has been used to prove innocence in rape and sexual assault cases on numerous occasions in courtrooms across the US.

Brooklyn lawyer Joyce David, who has used the defence herself in court, told the Sun-Sentinel she wasn’t convinced it was necessary for the court to view Patterson’s manhood in person. “Really, couldn’t they just make a mould or something?” she said.

Marquinez’s son, Omar Andrade, 41, told reporters outside court he was outraged by the development.

“(The defence claim is) totally false,” Mr Andrade said.

“He’s a desperate man trying to avoid being convicted for the crime. He’s trying to do anything to not go to jail.”

He described his mother as “loving” and a “great person” who did not deserve to die the way she had.

“She had no problems in her personal life or anything else to warrant anything like what happened to her,” he said.

Richard Henry Patterson, (pictured) 65, has admitted he choked his girlfriend, Francisca Marquinez, 60, to death on Oct. 28, 2015, but claims it happened accidentally during oral sex, and wants to show his penis to jurors as evidence.Source:Supplied

Patterson was arrested and charged with second degree murder in November 2015 following the discovery of Ms Marquinez’s body in the couple’s Brooklyn apartment on October 28.

Police allege Patterson’s lawyer rang them after her death to tell them the location of her body.

When detectives arrived at the flat, they found Ms Marquinez’s decomposing body lying on a bed and covered with a sheet.

A post mortem examination determined that she had been dead for eight to 24 hours before discovering her body.

Officers allegedly found a bag that was filled with paper towels covered in blood and semen inside the kitchen. Blood was also found inside the bedroom and on one of the victim’s fingers.

However, police also noted signs someone had attempted to clean the apartment recently, according to the arrest warrant tendered to court.

Jury selection in the trial is scheduled to begin on May 15. There has been no indication when the judge will rule on the penis motion.