The central message delivered in defence closings by barrister Astrid Haban-Beer was the jury should not believe the evidence of the prosecutor's key witness as he is a former drug dealer with a motive to lie.

On one side, she said, you had the accused Brendan Baker, 27, who, in a video played to the jury, gifted his grandmother a BMW.

On the other you had the police informant who had completed drug deals in his grandmother's home.

However federal prosecutor Darren Renton said this case could not be simplified into good people versus bad people.

"People that have done the wrong thing can do the right thing," Mr Renton said, referencing the man's switch from drug dealer to police informant.

He said all the defence had done was make sweeping statements the man had made up a story to save himself from prosecution.

The allegations are that Mr Baker approached the witness, an established drug dealer, and offered to supply him cheaper drugs. It is alleged they began working together to distribute drugs, which has led to 12 charges against Mr Baker including drug trafficking and importation.

Mr Baker has denied involvement in the drug trade and pleaded not guilty.

The jury was presented with recordings of conversations in person and on the phone and text messages between the men which the prosecution contends capture their partnership.

Mr Renton also pointed to an affluent lifestyle, captured in Mr Baker's various social media accounts, that was not supported by his declared income.

However, Ms Haban-Beer said the Mercedes AMG and various businesses, such as a Kingston cafe, could be explained by Mr Baker working several jobs and loans.

She admitted Mr Baker had attempted to make himself seem impressive on social media, but that was not a reason to convict him, she said.

She said the informant had provided vague information and needed to invent a compelling narrative to sell to police to keep himself out of jail.

She described the prosecution case as a Pro Hart painting, "splashing paint around here and there" and asking the jury to connect the dots.

Acting Chief Justice John Burns will address the jury on Friday before they enter deliberations.