It's hard to believe that a phone between Oscar Pistorius and an ex-girlfriend on the night that he later shot and killed girlfriend Reeva Steenkamp would have no bearing on his murder trial.

It's hard to believe that a phone between Oscar Pistorius and an ex-girlfriend on the night that he later shot and killed girlfriend Reeva Steenkamp would have no bearing on his murder trial.

That's what a prosecution source is saying in response to the shocking report from a new book about the trial titled "Behind the Door" by investigative reporters Barry Bateman and Mandy Wiener of the South African television station Eyewitness News.

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EWN.co.za reported that Pistorius had a nine-minute conversation with Jenna Edkins just minutes before arriving home to Steenkamp.

The Telegraph reported that Pistorius had an on-again, off-again romantic relationship for five years with Edkins from 2008 - which would put the end of that relationship sometime close to 2013. Pistorius shot and killed Steenkamp in the early morning hours of Valentine's Day, 2013 - or 45 days into 2013.

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According to Eyewitness News, Edkins' number had been saved under the name "Babyshoes," which the book claims is the reason the prosecution missed finding that evidence.

"... Investigators did not make a connection between Edkins' father's name (under which the phone was registered) and the athlete," EWN reported.

An unidentified member of the prosecution team, however, told EWN that Judge Thokozile would not have allowed the phone call as evidence in court because it would have been considered "character evidence."

According to the Telegraph, Judge Masipa "dismissed the records of WhatsApp conversations from Steenkamp's phone - which showed a sometimes tempestuous relationship - as normal ebbs and flows of 'fickle' human relationships."

In another strange development, Bateman and Wiener wrote in the book that Pistorius' brother, Carl, almost faced prosecution after police discovered he allegedly tampered with Pistorius' phone in the days after he shot Steenkamp.

EWN reported, "A study of the data extracted from Pistorius' personal phone shows the entire call history and every WhatsApp message had been deleted, as well as several messages sent to the device after the shooting.

"This phone was only handed to the police a full 12 days after Steenkamp was killed.

"In an attempt to track the whereabouts of the handset during that period, police investigators compared the service provider data of both Oscar and Carl's phones during that time.

"This is how they established that it was likely the athlete's brother had removed the device from the crime scene."

Investigators considered charging Carl Pistorius with defeating the ends of justice but ultimately declined to proceed with a case against him, EWN reported. No explanation was given behind that decision.

On Wednesday night, Pistorius' family and legal team issued a preemptive statement against the news that broke on Thursday.

"We are not sure of the allegations which are to be made or the source of such allegations, but we are not aware of any deletions having been affected by Oscar or effected on his instructions that could be relevant to this trial or could have impacted on this trial," the statement said.

"The relevance of the communications from Oscar's phones, iPad and laptop was properly dealt with by the court and ultimately played no role in the matter, this having been found by the court," Pistorius' representatives wrote in the statement.

A source for Pistorius' defense team indicated that the team was aware of the phone call and was prepared to call Edkins as a witness for the defense had the prosecution introduced the evidence.

The source told EWN that Pistorius and Edkins are just friends and the relationship no longer is romantic. In response to questions from EWN, Edkins said it's common knowledge that he has remained friends with her ex-boyfriend for years.

Masipa is scheduled to sentence Pistorius on a culpable murder charge on Oct. 13. He faces anywhere from a suspended sentence and a fine to 15 years in prison.

Do you think Oscar Pistorius' phone conversation with his ex-girlfriend on the night he shot and killed girlfriend Reeva Steenkamp is significant, and do you think his brother, Carl, should have been prosecuted on suspicion of tampering with evidence? Comment below or tell us @SportsWN.