As Oscar Pistorius awaits sentencing for his culpable homicide conviction, details continue to emerge surrounding the death of Reeva Steenkamp. South African journalists Barry Bateman and Mandy Weiner have written a book about the trial, purportedly exposing information that was not divulged in court.

The authors of “Behind the Door: The Oscar Pistorius and Reeva Steenkamp Story” claim Pistorius made a phone call to his ex-girlfriend Jenna Edkins just hours before shooting and killing Steenkamp on Valentine’s Day of last year, according to Eyewitness News, the publication that employes the writers. The double-amputee Olympian and Paralympian runner reportedly spoke to Edkins for nine minutes on Feb. 13, 2013, at about 6 p.m. local time. Pistorius shot and killed Steenkamp around 3 a.m. the next morning.

The phone call to Edkins wasn’t brought up by the prosecution during the trial. The authors say the police were unaware that Pistorius had talked to his ex-girlfriend because her phone was registered under her father’s name. Pistorius had Edkins’ number saved as “Babyshoes” on his phone.

Edkins declined to answer questions posed by Eyewitness News, saying only that it is common knowledge that she and Pistorius have remained friends.

Even if the prosecution have known about the call, it’s unlikely it would have had an impact in court. Judge Thokozile Masipa has said evidence indicating the couple had a rocky relationship would not influence her final verdict.

“Normal relationships are dynamic and unpredictable most of the time, while human beings are fickle,” Masipa said. “None of the evidence of a loving relationship, or a relationship turned sour, can assist this court.”

The book by Bateman and Weiner claims the call history on Pistorius’ phone was deleted by the time it got into the hands of authorities. Eyewitness News reported police suspected the athlete’s brother, Carl Pistorius, could have deleted the call history and other data, such as its WhatsApp record. The phone was missing for 12 days. Carl Pistorius was not charged with any crime.