Girlfriend ‘murdered’ footballer boyfriend in alleged murder-suicide plot after ‘relationship betrayal’

Warning: This article contains discussion of suicide which some readers may find distressing

There's a brand new volume in the anthology documentary series UNTOLD, which takes a deep dive into the extremely wild world of sports.

This season will focus on three new stories - one of which includes the harrowing tale which saw a girlfriend 'murder' her footballer boyfriend in an alleged murder-suicide plot after suffering a 'relationship betrayal'. Check out the official Netflix trailer here:

Steve 'Air' McNair was best known for his exciting run to the Super Bowl with the Tennessee Titans, who he played for from 1993 to 2005.

However, his career was stopped short in 2009 following his murder, aged just 36, which has left a whole load of unanswered questions still surrounding his death.

"People liked him. He smiled, he was quiet," said Jeff Fisher, McNair’s former NFL coach.

"He didn’t really like the cameras and interviews, but there was no question he had the capability to excel at this level."

The doc looks back at the shock Nashville Police discovered that the sportsman was murdered on July 4th, 2009, after suffering multiple gunshot wounds.

The documentary explores the rise of NFL quarterback, Steve McNair, and the perplexing details surrounding his shocking murder in 2009.(Netflix)

The NFL quarterback had been found shot in the head and alongside him was the body of a 20-year-old woman, later identified as Sahel 'Jenni' Kazemi, who was McNair's girlfriend at the time.

Despite the fact that McNair was married, he and Kazemi were seeing each other for six months.

"They started to really fall for each other, and it was genuine," said Emily Andrews, a friend of Kazemi. "They had conversations about adopting kids one day together and really building a life together."

A relative of Kazemi added: "She was happy with him. She said that he was getting divorced very soon, in about two weeks."

Police found that there were tensions within McNair and Kazemi's relationship when she reportedly found out McNair had been unfaithful after she discovered condoms in the condominium they co-owned.

McNair's girlfriend at the time, Sahel 'Jenni' Kazemi, was found to be responsible for both deaths in a murder-suicide case. (Netflix)

"I think he really broke her heart," Andrews revealed while Charles Robinson, a detective at the Nashville Police Department, added: "I think everything went downhill after Jenni started realising there was other women that Steve was also seeing."

It was also found that just two days before their death, Kazemi bought a handgun, which was found in the condo where the bodies were found.

An investigation found that Kazemi had shot him four times and then committed suicide.

However, a private investigator, Vincent Hill, challenged the Nashville Police Department’s investigation and questioned the nature of it and whether other suspects should have been questioned.

UNTOLD: The Murder of Air McNair is currently available to stream on Netflix.