Const. Kwesi Millington is facing one charge of perjury related to the testimony he gave at the Braidwood Inquiry back in 2009.
Millington's trial began in March 2014, after several delays. It was scheduled to finish Nov, 27 with closing arguments.
On Wednesday Special Prosecutor Scott Fenton told Justice William Ehrcke he needed more time.
Fenton explained that the Crown's key witness has suddenly located documents relevant to the case.
"It was one of these situations where they were thrust into our hands", Fenton told the court.
Fenton said it would take some time for the material to be studied and shared with Millington's defence lawyer.
The documents come from witness Janice Norgard, who alleges all four Mounties involved in Robert Dziekanski's death met secretly at her house before they all testified at the Braidwood Inquiry.
If true, all four could be found guilty of perjury because each told the Inquiry they had not met prior to testifying.
Norgard has already made an appearance at the separate perjury trial of former RCMP Cpl. Monty Robinson. During her testimony Norgard argued with Robinson's lawyer over documents which suggested she could be mistaken about the timing of the meeting.
Prosecutors have been working with Norgard to present her evidence since 2013. Fenton did not explain to the court why the team of lawyers had not discovered the documents sometime in the last year.
"There will be a ripple effect", Fenton said about the ability to conclude the trial.
"That's extremely vague", Justice Ehrcke replied.
Fenton was not ready to say the case could be concluded before the end of the year, and the lawyers started discussing dates in 2015.
Millington fired the Taser the night Dziekanski died at Vancouver International airport in 2007.
Ten separate allegations are contained in the single count of perjury filed against him.
The trial resumes next week.