Oscar Pistorius made a phone call to his ex-girlfriend shortly before he killed Reeva Steenkamp, according to new allegations not included in his trial. 

The recent claims will be proposed in the book "Behind the Door," written about the trial by two journalists who covered the case, Barry Bateman of "Eyewitness News" and Mandy Wiener. 

Pistorius allegedly deleted his entire call history and WhatsApp records after the murder. 

The evidence of his nine-minute call to ex-girlfriend Jenna Edkins was not used in court because Judge Thokozile Masipa would have deemed the call as character evidence so the prosecution source dismissed it, reported The Telegraph. 

Pistorius and Edkins dated on-and-off for five years. He reportedly was still seeing her and another woman when he met Reeva Steenkamp, who he shot on Valentine's Day last year. 

Police told The Telegraph that they were unaware the evidence even existed. 

The Telegraph speculates this new alleged evidence will put pressure on police to question the way the prosecution was conducted. 

Pistorius was convicted on Sept. 12 of manslaughter and will face up to 15 years in prison when sentenced on Oct. 13. The possibility still stands for him to be given a suspended sentence or to be ordered to complete community service.