* Pathologist takes stand on sixth day of murder trial
* Judge imposes broadcast blackout on autopsy details
* Steenkamp died of "multiple gun-shot wounds", court told
* Pistorius breaks down during pathologist testimony (Updates with vomiting, adds details on ammunition)
By Vanessa Romeo
PRETORIA, March 10 (Reuters) - Track star Oscar Pistorius, on trial for the murder of his girlfriend Reeva Steenkamp, wept and vomited into a bucket in a South African courtroom on Monday after hearing graphic details from her autopsy.
Pathologist Gert Saayman was interrupted several times by the 27-year-old Paralympic and Olympic athlete's sobbing and retching but the defence team argued against an adjournment, saying a break would not improve his state of mind.
Earlier, Judge Thokozile Masipa imposed a broadcast blackout on Saayman's testimony out of respect for Steenkamp's family and to prevent children from accidentally hearing its contents.
"Broadcast would compromise the privacy of the deceased, hurt the interests of the Steenkamps and be against the morals of society," Saayam said when he took the stand to ask for a temporary broadcast blackout of a trial that has so far been shown in its entirety on live television.
Masipa, who has been presiding over the week-long trial, extended the ban to live reporting on Twitter.
Pistorius, nicknamed "Bladerunner" for the special prosthetics he wears in competition, admits he shot 29-year-old Steenkamp, a model and law graduate, but argues that it was a tragic case of mistaken identity and that he thought she was an intruder who had broken in to his luxury Pretoria home.
In his testimony, Saayman confirmed that Steenkamp was hit in the head, arm and hip by three shots fired through the locked door of a toilet cubicle. A fourth round fired by Pistorius missed.
Saayman also disclosed Pistorius was using 'hollow-point' rounds, ammunition designed to disintegrate on impact with tissue to cause maximum damage.
Her right upper arm was shattered, the hip wound could well have been fatal, while that to her head would have incapacitated her immediately, he added. No blood was found in her airways, suggesting she breathed only a few times before dying.
In between bouts of sobbing and retching, Pistorius sat with his head bowed, covering his ears with his hands and a white handkerchief in an attempt to block out Saayman's testimony.
Saayman is the first expert to testify at the trial, which has so far heard several witnesses who reported hearing a woman screaming before a volley of shots in the early hours of Feb. 14 - Valentine's Day - at Pistorius' home.
The killing stunned South Africa and the millions of Pistorius supporters around the world who admired the athlete as a symbol of triumph over physical adversity.
He had his disabled lower legs amputated as a baby but - running on carbon fibre prosthetic "blades" - made it to the semi-final of the 400 metres at the London 2012 Olympics competing against able-bodied sprinters.
If found guilty of murder, he faces at least 25 years behind bars. (Additional reporting by Lynette Ndabambi, Writing by Ed Cropley, Editing by David Dolan and Angus MacSwan)