Pistorius' agent Peet van Zyl and coach Ampie Louw couldn't be reached while Pistorius' own cellphone went straight to an answerphone service.
Pistorius' former coach, Andrea Giannini, said he hopes it was "just a tragic accident."
"No matter how bad the situation was, Oscar always stayed calm and positive," Giannini told the AP in Italy. "Whenever he was tired or nervous he was still extremely nice to people. I never saw him violent."
Gianni said he believed that Pistorius had been dating Steenkamp for "a few months."
"I know he had more than one flirt over the last year," Giannini said.
Paolo Urbani, the mayor of the Italian town of Gemona where Pistorius had a training base and prepared for the London Olympics from said he is shocked as Pistorius was "a delightful person."
"The news shocked not only me personally but also the whole of Gemona and the region," Urbani said. "It come(s) as a huge shock to everyone who knew him. I was woken up this morning by a phone call from his general manager, who called me to let me know so that I didn't find out about it from the news."
Police said that earlier reports that Steenkamp may have been mistaken for a burglar by Pistorius did not come from the police. Several local media outlets had initially reported that the shooting may have been accidental.
"It would be very premature and very irresponsible of me to say what actually has happened," Beukes said. "There have been allegations. We are not sure."
Beukes also said there had been previous incidents and "allegations of a domestic nature" at the home of the Olympic star and double-amputee runner, who is one of South Africa's and the world's most famous sportsmen and made history at the London Games last year by being the first double-amputee runner to compete at the Olympics.