A criminal case has dramatically collapsed after ACT police officers unlawfully raided a Canberra grow house.
And in extraordinary allegations aired in court, police are alleged to have recruited a reluctant civilian informant into their investigation and pressured her to go into the grow house to check for plants.
A court has heard police entered the Calwell home minutes after the informant confirmed there were still plants there, using emergency search powers since found to have been exercised unlawfully.
Later, the informant's identity as the man's sister was exposed, with her name appearing in court documents as a possible witness and police revealing in open court that she was the informant.
A court has now ordered evidence obtained in the illegal search be excluded from the criminal trial.
That includes the 119 seized cannabis plants and seedlings and his police interview, during which he made damning admissions while explaining how he was growing the plants to treat his pain.
With the fundamental evidence now excluded prosecutors have abandoned the case.
It was the 33-year-old Calwell man's sister who first tipped police off about his cannabis plants.
The sister told the ACT Supreme Court last week that she was worried about him and wanted him to get help, and that she wanted and believed her brother would be ordered into rehabilitation.
She wanted to remain anonymous and believed he had only about seven to 10 plants at the home.
But the effort to get her brother help would soon spin out of control.
After the illegal raid police charged the man with cultivating a commercial quantity of cannabis to sell, a crime carrying 25 years jail.
At a pretrial hearing last week to exclude evidence from the trial, the court heard the sister had called police in November 2017 asking them to do something.
The police gave evidence that the sister told them her brother had left the house and said “I think he’s selling them” or at least disposing of them, and that they believed his former partner might be involved.
Police said they acted then to enter the home under emergency search powers.
Those powers require an officer to believe it is necessary to enter to prevent the loss of evidence and that the situation was so serious and so urgent it could not wait for a warrant.
One officer agreed under cross-examination that the emergency search could only be exercised in a genuine emergency, which included where it wasn't possible to get a warrant without risking loss of evidence.
But the police had not tried to get a warrant over the telephone, a process the officer agreed can take less than an hour.
After the police gave evidence that day, lawyers for the man called the sister to court at the last minute, and she gave extraordinary evidence, having up to then refusing to give a statement.
The woman, a public servant, admitted she had made the calls to police in an effort to get her brother help.
She also said that when she had called police that day she was pressured to go to her brother’s home and confirm the plants were still there, so that police could act straight away.
She was hesitant and told the officer she didn't want her brother to know it was her.
But the woman said she asked her boss permission to leave work and when police called her back during the visit she said there weren’t as many plants as first thought, a few baby plants.
But police had then allegedly urged her to get out of the house because they were on their way.
The sister denied telling police her brother had left the house to sell the plants or that she believed he was involved in selling at all, and denied saying the former partner was involved at all.
The court earlier heard that the police officer who took the call made no notes of the conversation.
At the end of the day’s hearing Justice David Mossop exercised his discretion to exclude from the trial evidence obtained unlawfully. Prosecutors abandoned the case this week.
The man's defence lawyer Charlene Harris, from Aulich Law, told The Canberra Times the case needed to be dismissed.
"Police investigative powers can infringe our basic rights," she said.
"When safeguards for those rights are ignored, such as conducting an emergency search without a lawful basis, the case must be dismissed in order to send the message that noncompliance will not be tolerated."
In a statement, police defended their record.
"The most recent assessment of criminal matters brought to court by ACT Policing has seen 95.6 per cent of matters successfully proven," a spokesman said.