Former NT police commissioner John McRoberts has been jailed for 12 months after being found guilty of attempting to pervert the course of justice.

The 59-year-old was found guilty in the NT Supreme Court in Darwin last month of intending to deflect and frustrate a fraud investigation into his former lover, travel agent Alexandra Xana Kamitsis.

Justice Dean Mildren jailed McRoberts for three years, to be suspended after one year.

His lawyer Anthony Elliott immediately applied to appeal and for a bail application on Wednesday that would keep McRoberts out of jail in the short term.

The former police boss knew he was breaching the police code of conduct and acting illegally but did it anyway over a period of months, Justice Mildren said.

That included blocking a raid on Kamitsi’s business, intending to cover up his sexual relationship with her and, consequently, her illegal behaviour.

Kamitsis was herself jailed in the NT’s largest-ever fraud investigation.

Numerous Darwin travel agents were found to have been greedily defrauding a government pensioner concession scheme of millions of taxpayer dollars.

Unfortunately for McRoberts, police focused their investigation on Kamitsis, who in one case had invoiced the health department more than $3000 for flights that actually cost $1000.

She had even charged the government for flights for pensioners without them knowing.

McRoberts, who lied when directly asked to clarify rumours about the affair, asked his detectives why they were targeting Kamitsis.

In meetings with politician and bureaucrats, he also pushed for an end to the criminal probe and for a civil remedy instead, wanting dishonest travel agents to be allowed to simply pay back the money.

Justice Mildren said McRoberts was guilty of a gross misuse of power that “struck at the heart of justice”, including to protect himself from scandal and his high-paying job

“You were as police commissioner expected to uphold the law, not actively breach it,” Justice Mildren said in his hour-long sentencing statement. He added the crime was too serious not to involve time in jail.

-AAP