Reports from the athlete's native South Africa claim that the bat is a key piece of evidence but police investigating the model's killing have denied leaking it.
"We are not commenting on anything in the newspapers today as the case is still before the court," said a police spokesperson. "They are insinuating they got the information from the police. They did not."
The country's City Press newspaper cites a source close to the investigation claiming that Steenkamp's skull was crushed and police are requesting that Pistorius undergoes a drug test.
Other reports speculate that Steenkamp used the bat to defend herself from her alleged assailant.
Pistorius's agent Peet van Zyl refused to comment on the reports, claiming he has "not read a lot of the media" but adding that his client has received support from fans around the world.
The sprinter is due in court in Pretoria on Tuesday to apply for bail. Steenkamp will be cremated at a private ceremony that same day.