Two Winnipeg police officers have denied allegations that they fabricated evidence and obstructed justice in their investigation of a suspected drug dealer.

Consts. Graeme Beattie, 30, and Paul Clark, 41, pleaded not guilty to charges of fabricating evidence, attempting to obstruct justice, and public mischief at the start of a preliminary inquiry into their criminal case on Monday.

A mandatory publication ban on the preliminary hearing prevents the reporting of any evidence given. The pre-trial hearing is to determine whether the Crown's case is strong enough to go to trial.

Manitoba Justice has hired lawyer Robert Tapper to act as an independent prosecutor.

The officers are accused of falsifying notes and reports that led to a man being charged with drug trafficking in May 2008, according to court documents obtained by CBC News when Clark and Beattie were formally charged.

The case against the suspected drug dealer, 20, wound its way through the courts for months until the Crown stayed the charges against the man in October 2008 on the day his preliminary hearing was set to begin.

An internal police service investigation was launched a month later, and the officers were charged in April 2009.

The mischief charges stem from the alleged falsified reports, which polices said caused officers to unnecessarily investigate a drug-trafficking offence.

Beattie and Clark are currently assigned to administrative desk duties within the police force. Each had three years of experience with the Winnipeg police at the time they were charged.