Prosecutors allege Mr Pickton is Canada's worst serial killer

They say the pig farmer told an undercover police officer he wanted to kill one more to make it an "even 50".

Mr Pickton is accused of murdering 26 women - all of whom were prostitutes and drug addicts - who disappeared over a period of more than a decade.

The 57-year-old is initially being tried for the murder of six of the women. He has pleaded not guilty.

Mr Pickton will be tried in connection with the other 20 women later, because a judge decided that the volume of evidence could have overwhelmed the jury, and that the case ought to be split into two.

The heads of the individuals had been cut in two, vertically

Derrill Prevett, prosecutor

This trial is expected to last for at least a year.

Mr Pickton has been in jail since his arrest during an elaborate police investigation of dozens of missing women from Vancouver's Downtown Eastside.

Police have identified more than 60 missing women in the area and are continuing their investigation. Prosecutors have not ruled out further charges against Mr Pickton.

His lawyer, Peter Ritchie, has called on the jury to keep an open mind about the case.

Body parts

The judge presiding over the case has told jurors they must brace themselves for "shocking" testimony.

Already they have heard opening statements containing graphic allegations against Mr Pickton.

There has been huge anticipation in Canada ahead of the case

The prosecutor, Derrill Prevett, said the heads and other body parts of two of the victims were found in a freezer during a 2002 police search of Mr Pickton's farm in Port Coquitlam, near Vancouver.

"The heads of the individuals had been cut in two, vertically," he said.

"With the skulls were left and right hands and the front parts of the left and right feet."

Mr Prevett added that both skulls had bullet wounds.

Investigators also found a gun at the farm, which had a sex toy attached to the barrel.

The sex toy had DNA of Mr Pickton and one of the alleged victims, the prosecutor said.

Mr Prevett also told the court Mr Pickton had described himself to the undercover officer as a serial killer.

None of the evidence had been revealed in the Canadian media until the trial began, after a court order ruled that its publication could prejudice the trial.

Therefore there has been huge anticipation in Canada ahead of the case.

If Mr Pickton is found guilty he faces life in prison.