Oscar Pistorius made a private phone call to an ex-girlfriend shortly before he killed Reeva Steenkamp, a new book claims.

The athlete, who was found guilty of culpable homicide but cleared of murder in Pretoria last month, apparently spoke to fellow Olympian Jenna Edkins for nine minutes on Valentine’s Day in 2013.

The conversation was not included as evidence during his six-month trial because police were apparently unaware it had ever existed, according to the book.

The number used by Edkins had supposedly been registered in her father’s name and was saved in Pistorius’ contacts as “Babyshoes”.

It has been claimed that officers investigating Steenkamp’s death had failed to make the connection between the name “Babyshoes” and Edkins.

Oscar Pistorius: Career in pictures Show all 34 1 /34 Oscar Pistorius: Career in pictures Oscar Pistorius: Career in pictures Oscar Pistorius in Greece Oscar Pistorius wins the 200m T44 for Men during the Athens 2004 Paralympic Games at the Olympic Stadium in Athens, 2004 Oscar Pistorius: Career in pictures Oscar Pistorius in Greece Oscar Pistorius at the Olympic Stadium in Athens, 2004 Oscar Pistorius: Career in pictures Oscar Pistorius in Manchester Oscar Pistorius celebrates winning his second gold medal during the VISA Paralympic World Cup Athletics at the Sport City Stadium in Manchester, 2006 Oscar Pistorius: Career in pictures Oscar Pistorius in Manchester Oscar Pistorius shows his gold medal after winning the T44 200 m for men at the Visa Paralympic world cup at the Manchester Regional Arena, 2007 Oscar Pistorius: Career in pictures Oscar Pistorius competes in race Oscar Pistorius competing in the men's 400m race B, 2007 Oscar Pistorius: Career in pictures Oscar Pistorius in Rome Oscar Pistorius settles in the blocks before winning the Mens 400m 'B' race during the IAAF Golden Gala at The Olympic Stadium in Rome, 2007 Oscar Pistorius: Career in pictures Oscar Pistorius in Rome Oscar Pistorius poses during the broadcast 'Piazza grande' on Italian TV state channel 'Rai 1' in Rome, 2008 Oscar Pistorius: Career in pictures Oscar Pistorius in St.Petersburg (L to R) Bryan Habana, Cuba Gooding Jr and Oscar Pistorius during the Laureus welcome reception at Gimnazya in St.Petersburg, 2008 Oscar Pistorius: Career in pictures Oscar Pistorius arrives at the Court of Arbitration for Sport (CAS) in Lausanne Oscar Pistorius arrives at the Court of Arbitration for Sport (CAS) in Lausanne to appeal his case on the second day of his hearing as he was told by the International Association of Athletics Federations (IAAF) that he could not compete in their events because the artificial legs he uses gives him an unfair advantage, 2008 Oscar Pistorius: Career in pictures Oscar Pistorius runs during a training session Oscar Pistorius runs during a training session on the track of Emmeloord, 2008 Oscar Pistorius: Career in pictures Oscar Pistorius in Germany Oscar Pistorius compete during the 400 meter race at the German disabled athletics championships in Berlin, 2008 Oscar Pistorius: Career in pictures Oscar Pistorius in Italy Oscar Pistorius of South Africa relaxes prior to the 400m race in his quest to make the Olympic qualifying time of 45.55 during the Notturna di Milano International Athletics Meeting at the Arena Gianni Brera in Milan, 2008 Oscar Pistorius: Career in pictures Oscar Pistorius in China Oscar Pistorius speaks at a press conference for the 2008 Beijing Paralympic Games in Beijing, 2008 Oscar Pistorius: Career in pictures Oscar Pistorius in China Oscar Pistorius of South Africa celebrates after winning the gold medal in the Men's 100m T44 Final Athletics event at the National Stadium during day three of the 2008 Paralympic Games in Beijing, 2008 Oscar Pistorius: Career in pictures Oscar Pistorius in China Oscar Pistorious (L) leads Heros Marai (C) of Italy and Christoph Bausch (R) of Switzerland in the heats of the men's 100 metre T44 classification race at the 2008 Beijing Paralympic Games in Beijing, 2008 Oscar Pistorius: Career in pictures Oscar Pistorius and Nelson Mandela in South Africa Oscar Pistorius and former South African President, Nelson Mandela in South Africa, 2009 Oscar Pistorius: Career in pictures Oscar Pistorius in Norway Oscar Pistorius looks on prior to the 400m B-final during the IAAF Golden League Bislett Games in Oslo, 2009 Oscar Pistorius: Career in pictures Oscar Pistorius in London Oscar Pistorius reacts after winning the men's 400 metres T44 final race with a new world record time of 47.04 sec during the Diamond League athletics meeting at Crystal Palace in London, 2010 Oscar Pistorius: Career in pictures Oscar Pistorius in New Zealand Oscar Pistorius of South Africa celebrates receiving his gold medal after winning the Men's 200m T44 final during day three of the IPC Athletics Championships at QE II Park in Christchurch, New Zealand, 2011 Oscar Pistorius: Career in pictures Oscar Pistorius in New Zealand (L-R) Arnu Fourie, Henry Roos, Oscar Pistorius and Mike Samkelo Radebe of South Africa celebrate after winning the Men's 4x100m Relay T42-46 final during day eight of the IPC Athletics Championships at QE II Park in Christchurch, New Zealand, 2011 Oscar Pistorius: Career in pictures Oscar Pistorius in New Zealand Oscar Pistorius of South Africa poses with his medals during day eight of the IPC Athletics Championships at QE II Park in Christchurch, New Zealand, 2011 Oscar Pistorius: Career in pictures Oscar Pistorius in South Africa Oscar Pistorius in action during the 400m during day 5 of The Nedbank National Championships for the Physically Disabled from Olympia Park Stadium in Rustenburg, 2011 Oscar Pistorius: Career in pictures Oscar Pistorius in Czech Republic Oscar Pistorius warms up before the men's 400m event at the Zlata Tretra (Golden Spike) athletics meeting in the eastern Czech city of Ostrava, 2011 Oscar Pistorius: Career in pictures Oscar Pistorius in New York Oscar Pistorius attends the Eva Mendes launch of her new campaign for Angel by Thierry Mugler at IAC Building in New York, 2011 Oscar Pistorius: Career in pictures Oscar Pistorius in South Korea Oscar Pistorius of South Africa speaks with Olympic gold medalist Michael Johnson of the United States during a media gathering at the Novatel Hotel prior to the 13th IAAF World Athletics Championships Daegu 2011 in Daegu, South Korea, 2011 Oscar Pistorius: Career in pictures Oscar Pistorius in South Korea Oscar Pistorius prepares to settle into the blocks to compete in the men's 400 metres heats at the International Association of Athletics Federations (IAAF) World Championships in Daegu, 2011 Oscar Pistorius: Career in pictures Oscar Pistorius in London South African sprint runner known as 'Blade Runner' Oscar Pistorius (C) poses for photographers with Paralympians ahead of the international Paralympic Day in central London, 2011 Oscar Pistorius: Career in pictures Oscar Pistorius in London Oscar Pistorius poses in the press room with his Laureus World Sportsperson of the Year with a Disability trophy at the 2012 Laureus World Sports Awards at Queen Elizabeth II Conference Centre in London, 2012 Oscar Pistorius: Career in pictures Oscar Pistorius in London Oscar Pistorius of South Africa competes in the Men's 400m Round 1 heat on Day 8 of the 2012 London Olympic Games at the Olympic Stadium in London, 2012 Oscar Pistorius: Career in pictures Oscar Pistorius receives his honorary doctorate Oscar Pistorius holds his scroll after receiving his honorary doctorate from Strathclyde University in the Barony Hall in Glasgow, 2012 Oscar Pistorius: Career in pictures Oscar Pistorius with his girlfriend Oscar Pistorius posing next to his girlfriend Reeva Steenkamp at Melrose Arch in Johannesburg, 2013 Oscar Pistorius: Career in pictures Oscar Pistorius in court Oscar Pistorius hides his face in his hands in the court room during his hearing on charge of murdering his model girlfriend Reeva Steenkamp at the Magistrate Court in Pretoria, 2013 Oscar Pistorius: Career in pictures Oscar Pistorius in court Oscar Pistorius stands in the Magistrate Court in Pretoria after appearing for the first time since being freed on bail over the Valentine's Day killing of his model girlfriend, 2013 Oscar Pistorius: Career in pictures Oscar Pistorius in court Oscar Pistorius appeared on charges of murdering his model girlfriend Reeva Steenkamp, 2013

The phone on which Pistorius called Edkins was one of two handsets, and was apparently removed from the crime scene for almost two weeks before it was handed over to the authorities.

By the time it was given in, its entire call history had allegedly been wiped.

As a result, Edkins was never questioned by the authorities and therefore did not provide a statement.

The apparent addition to Pistorius' story is set to be published in Behind the Door – a book about the trial by two leading journalists on the case, Barry Bateman of Eyewitness News and Mandy Wiener.

According to Bateman, the prosecution has so far declined to comment on how the evidence was missed.

However, The Telegraph reports that a prosecution source has since dismissed the evidence, saying that Judge Thokozile Masipa would have considered the call character evidence and disallowed it.

The Pistorius family said that they “were not aware of any deletions that could be relevant to this trial, or have impacted on this trial”.

Pistorius and Edkins apparently enjoyed a turbulent relationship dating back to 2008.

The day after news of Steenkamp’s death broke, Edkins posted the following on Twitter:

Pistorius was convicted of culpable homicide – the equivalent of manslaughter – on 12 September.