Former NT police commissioner John McRoberts will try and regain his freedom after he was convicted and jailed for 12 months for attempting to pervert the course of justice.
Justice Dean Mildren jailed McRoberts in the Supreme Court in Darwin on Tuesday for three years, to be suspended after one year.
His lawyer Anthony Elliott immediately applied to appeal and for a bail application on Wednesday but McRoberts spent Monday and Tuesday night behind bars.
Justice Mildren told the 59-year-old he was supposed to uphold the law and not break it, and his offending was too serious not to involve "some period of actual custody".
He was found guilty by a jury last month over his efforts to derail a fraud investigation into his former lover, travel agent Xana Kamitsis, to protect himself from losing his job and scandal.
When he discovered Kamitsis was the target in a major investigation into numerous Darwin travel agents found to be rorting a government pensioner concession scheme, he began to deflect and frustrate it, blocking a raid on her business.
The pair were in relationships with other people.
Justice Mildren told McRoberts, who rebuked his officers after Kamitsis was filmed by media while arrested, he was guilty of a gross misuse of power that "struck at the heart of justice".
The case was unusual, because such cases normally involved threats, bribery and cover-ups, but no less serious, he said.
"Particularly when the offender in this case is none other than the commissioner of police who misused their powers for an improper purpose," Justice Mildren said.
Kamitsis was jailed in December 2015, in the NT's largest-ever fraud investigation.