According to the UK's Daily Telegraph, they told ITV News that they had never doubted their brother's version of events.

"There's not an inkling of reservation. I believe what Oscar says," Carl said.

Aimee, who works for financial services company Investec, said: "My first thoughts were that, knowing my brother and the kind of person he is, as well as his fears, [he] must have thought it was an intruder."

They complained of "negative media, twisted truths and untruths" and spoke of the vitriol the Pistorius family has endured on social media.

Carl told eNCA: "The threats are something we take seriously, especially threats that have been made towards Oscar. When people speak out in hate, we try to remind ourselves to respond in love."

When CNN news anchor Robyn Curnow noted that "this might not end with the sentencing; there might be an appeal", Aimee said: "It's never going to be over."

"Something like this changes my brother's life, our lives, the Steenkamps', their friends'. No one who's been close to the situation can just overcome it and it's something my brother will carry with him forever."

Aimee told eNCA legal reporter Karyn Maughan that she hoped the Steenkamps realised how much her family had cared about Reeva.

Said Aimee: "[She was] loved and accepted as part of our family in the short time that she was with us.

"She had a wonderful charisma and zest for life that she just exuded and it was easy to fall in love with her ."

Reeva's uncle, Mike Steenkamp, said yesterday: "The past few weeks have taken a very heavy toll on both Barry and June [Steenkamp] .

"We are all affected and are trying to be strong for each other."