A trial into alleged perjury committed by two Winnipeg police officers as part of a drug investigation and subsequent prosecution opened Monday afternoon.

"This is an unusual case," independent Crown prosecutor, Robert Tapper, told the eight-woman, four-man jury who will decide the fate of Consts. Jess Zebrun, 33, and Peter O'Kane, 40. Both have pleaded not guilty.

"I'm going to ask you to convict these two officers of lying under oath," Tapper said.

The constables are accused of giving misleading or false statements under oath at the 2006 preliminary inquiry of two men accused of drug trafficking after room 1707 at the Fairmont Hotel was raided by police in Winnipeg in July 2005.

The case fell apart after the perjury allegations came to light.

"A very serious drug trafficker could not be brought to justice," Tapper said.

O'Kane is also accused of lying to a provincial magistrate in his application to obtain a search warrant allowing officers to enter the hotel room in the first place.

Slightly less than a kilogram of crack cocaine and about $18,000 in cash were seized from the room as part of the botched investigation.

Both officers have been working desk jobs since they were charged in January 2008 following a lengthy internal police investigation.

Tapper said he plans to present a range of evidence as the trial proceeds over the next two weeks, including GPS data from police cruiser cars and electronic pass key information from Winnipeg's Public Safety Building.

"I'm going to tell you they were not where they say they were," he said. "Where they were not is relevant to the case," he said.

The trial's first witness for the Crown was Sgt. Morgan Hudson, supervisor of the police service unit that manages and tracks payments made to registered confidential informants.

Hudson testified police records showed neither O'Kane nor Zebrun had such an informant relating to the Fairmont drug investigation.

Defence lawyers contended many police informants don't register with the police department out of fear they would be found out. Hudson agreed.

"That's a fear — being found out that you're providing information to us," he testified.

Some officers pay informants for information out of their own pockets, Hudson said.

"I know I've paid out of pocket ... cash, the odd meal," the 27-year-officer said of his own experiences working in the vice unit.

"You gotta get the job done," he testified.