Former NT Police Commissioner John McRoberts faces criminal charges

The high-profile trial of former Northern Territory Police Commissioner John McRoberts has begun in the Supreme Court.

Mr McRoberts has pleaded not guilty to one count of attempting to pervert the course of justice.

He's accused of interfering with an investigation into the suspected rorting of a taxpayer-funded pension travel scheme in 2014.

In his opening address, Prosecutor Michael McHugh SC said the crown would show text messages that reveal Mr McRoberts was an "intimate friend" of one of the targets, travel agent Xana Kamitsis.

"The accused and Kamitsis had a personal relationship, which at some time prior to 2014 had involved sexual intimacy," he said.

The court heard the top cop accepted gifts from the travel agent, who was also the chair of NT Crime Stoppers.

Mr McHugh told the jury Mr McRoberts deliberately failed to disclose the full extent of his relationship with Kamitsis, and instead sought to "deflect and frustrate" the criminal probe.

A who's who of senior police, prosecutors and politicians will be called as witnesses during the five-week trial.