Olympic heptathlon champion Jessica Ennis: "Woken up to the horrendous news about Oscar Pistorius mistakenly shooting his girlfriend. What an awful tragedy."
Sydney Olympics bronze medallist Katharine Merry: "One of the nicest guys, true gent....omg .....in shock for oscar and this situation. Imagine, just imagine... Still lying in bed staring at the ceiling........Really?? Really?"
Oscar’s father Henke Pistorius: "He is a bit emotional, but he is fine."
Pistorius’s agent, Peet van Zyl, told the Daily Telegraph: "I hope I can have access to him at the police station. At this point in time I can't give any details about what has happened. Oscar is a humble person and a lovely guy - I'm sure what's happened has been a terrible mistake but I really don't have the details at the moment."
Steenkamp’s publicist Sarit Tomlinson: "She was the sweetest human being and an absolute angel on earth. She was the kindest, most unbelievable girl."
Runner’s World magazine editor Mike Finch told Sky News: "If anybody can overcome this sort of thing it's probably Oscar. He’s had to deal with a lot in his life. He had a mother that died when he was very young, he obviously has his disability, but yet he's been amazing from a South African perspective as an ambassador. There is a certain school of people that don’t particularly like him, but I think today everybody has kind of rallied round him."
A Nike spokesman: "The company are saddened by the news, but we have no further comment to make at this stage.”
South Africa's Sports Confederation and Olympic Committee: "Our deepest sympathy and condolences have been expressed to the families of all concerned.”
Local broadcaster Daniel Silke told the BBC: "Many South Africans live in fear of violent crime, there's a high crime rate in the country and South Africans are often on edge in their home, particularly in the early hours of the morning when they hear noise. This has occurred in an atmosphere in South Africa in which crime again is at the forefront of the public debate, personal safety is again at the forefront of everybody's concerns."
Fellow South African model, and friend of Steenkamp’s, Jo-Ann Strauss: "This highlights how unsafe most South Africans feel because of crime."
Radio 702 talk show host, Redi Thlabi: "Expressing our sadness at the tragedy and talking broadly about gun ownership. Nobody is judging Oscar."