A corrupt Sydney private eye was sentenced to a year-long jail term after using the guise of an Australian Federal Police agent to taunt a 77-year-old woman.

The intimidating hoax began when the woman challenged Brett Sutcliffe, 28, for parking in a disabled parking zone outside her North Bondi residence.

Sutcliffe, the then director of a private investigation firm named Spousebusters, recorded the incident from a surveillance device in his parked car. The woman had requested Sutcliffe move so she could unload her shopping but the Spousebuster told her he couldn’t because he was an investigator.

The woman received a letter on AFP letterhead, signed by “Risk Officer 34324421234″, warning that she had “wrongly interfered” with an AFP investigation.

“The man you spoke to that was parked in your street was a federal agent working on an investigation regarding matters of national security,” the letter said.

Telling her neighbours of his presence “may have led to ruining months of surveillance and investigation”.

“This letter serves as your first and last warning about such matters although if it is found your actions have led to this investigation being compromised, you will be arrested and charged with obstruction of justice, harbouring of criminals as well as many other offences”.

The last line said the outcome of the matter would be advised within three weeks.

Weeks after receiving the letter, the woman was watching a current affairs story on Spousebusters when she recognised Sutcliffe as the “federal agent” outside her home.

In the Downing Centre Local Court today, Magistrate Pat O’Shane fined him $5,000 and jailed him for 12 months, ruling he would be eligible for release after nine months.

But she later granted him conditional bail, pending the hearing of a sentence appeal in the District Court.

At an earlier hearing, she said the incident “reeks of immaturity and an overwhelming sense of self-importance”.

Sutcliffe’s lawyer, Shane McAnulty, agreed the letter showed “significant immaturity” and could only put it down to Sutcliffe’s work pressure at the time.

He said the NSW Police Commissioner had cancelled Sutcliffe’s security licences and he was no longer involved with Spousebusters.