The arrest of Oscar Pistorius on a murder charge was greeted with disbelief around the world by athletes and Paralympians who know the blade runner.
South African superstar Pistorius (26) won two gold medals and a silver at the Paralympic Games in London last summer – where he spent time with local gold medal-winning athletes Michael McKillop and Jason Smyth. Michael, who triumphed for Ireland in the 800m and 1500m in the T37 class, tweeted a photo of himself with Pistorius.
The Glengormley man (23) wrote under it: "Sad to hear the news about Oscar Pistorius #Gentleman #Shocked #legend #FingersCrossed" He also described Pistorius "the most harmless man you will ever meet. #Kind #respectful #Sad"
The Paralympic and Olympic sprinter is a sporting hero at home and a high-profile inspiration abroad for his lifelong determination to transcend physical boundaries.
Eglinton runner Jason – regarded as the Usain Bolt of Paralympics – also used the social network to express his disbelief.
"What a shocking story," the 25-year-old posted.
Athletes joined fans in paying tribute to Miss Steenkamp.
Olympic heptathlon champion Jessica Ennis spoke of her shock on Twitter, describing the news as "an awful tragedy".
Sydney Olympics gold medal heptathlete Denise Lewis said: "Not a good morning athletics fans. News reports on Oscar Pistorius are unbelievable."
London 2012 Paralympic 200m champion Richard Whitehead tweeted: "Shocking news this morning regards my buddy Oscar P. What a tragedy! Unbelievable. I'm speechless."
Britain's Paralympic male and female discus champions also went online to relay their shock.
Aled Davies wrote on Twitter: "Wow... Crazy news about Oscar... Devastating and speechless...", while Josie Pearson simply stated it was "Tragic..."
Wheelchair racer Shelly Woods, silver medallist in the London 2012 Paralympic marathon, tweeted: "...very very sad"
The International Paralympic Committee (IPC) said it would be "inappropriate" to comment as it is a police matter.
The IPC statement added: "At this time the IPC would like to offer its deepest sympathy and condolences to all families involved in this case."