(CNN) -- Photographs purportedly showing the blood-spattered bathroom where Olympian Oscar Pistorius fatally shot girlfriend Reeva Steenkamp have emerged, apparently showing the scene of the killing for the first time.
The photos surfaced just days before the double amputee track star is due to appear in court, charged with murdering Steenkamp in his Pretoria home in the early hours of February 14.
The images published by Sky News show a trail of blood leading from a bathroom; blood on the walls, stairs and a couch inside the house, and a Valentine's Day card with "Ozzy" written on it -- Steenkamp's nickname for her sprinter boyfriend.
The photo of the bathroom shows a toilet covered in blood, a door with a missing panel and what appear to be two police-marked bullet holes below the level of the door's handle. CNN has not been able to independently confirm the authenticity of the photos, and police spokesman Brigadiere Phuti Setati declined to comment on how Sky News obtained the pictures.
The runner says he thought there was an intruder in the house and, fearful of being attacked, ran on his stumps to the bathroom, where he shot through the door from a relatively low angle four times. It was only upon returning to his bedroom, Pistorius says, that he realized Steenkamp was not in bed and that she had been the one in the bathroom.
The state says it was premeditated murder -- that Pistorius had an argument with Steenkamp then put on his prosthetic legs, walked to the bathroom, and shot through the door from a relatively higher angle, intentionally killing his girlfriend.
CNN's Robyn Curnow says a number of questions remain about the photos. "The door was removed quickly from the scene of the crime, but appears to have been reconstructed here, so it's unclear when the photos were taken and whether this is a reconstruction.
"These photos have also not been seen by Oscar Pistorius' legal team, and their release to journalists will raise questions about whether police corruption may have been involved," she said.
The police investigation into the killing has been beset by problems and scandals since the start.
Hilton Botha, the original lead investigator, admitted during Pistorius' bail hearing that police had failed to wear protective shoe covers at the crime scene because they had run out of them, and that it was possible evidence had been damaged as a result.
Botha also drew audible gasps from the packed courtroom when he testified that testosterone had been found at Pistorius' house, before being forced to admit that he hadn't actually read the full name of the substance. The sprinter's lawyers testified that the substance was an herbal remedy.
The Paralympian's lawyers also got Botha to acknowledge that investigators had failed to collect any evidence that counters Pistorius' argument that he mistakenly shot Steenkamp.
Things took a turn for the surreal near the end of the bail hearing when it emerged that Botha himself had been charged with seven counts of attempted murder for firing on a minibus full of people in 2011. Those charges had been withdrawn pending further investigation, but prosecutors reinstated them and he was pulled off the Pistorius case the day before the sprinter was granted bail.
Curnow says the timing of the release of the crime scene photos is especially significant, given that prosecutors are expected to ask magistrates next week to postpone the case pending further investigations.
"A legal expert has told me all indications are that the state's case against Pistorius is really quite thin at the moment," Curnow said. "It's possible that the publication of these photos will delay the trial still further."
Police spokesman Setati told CNN: "Nothing will distract the detectives from the case. They will remain on course to make sure that they secure a murder conviction."
CNN Wires contributed to this report.