Basically I am asking this question for someone else.
7 months ago police went to this person's house and they found 20 plants of cannabis, tools for growing, a scale and £6000 cash money, then they took him to police station with all the evidences. He said that all 20 plants were for his personal use and money was what he has been saved.
Finally they did let him go and told him that we will ask you to come back for another interview. After a couple of months, one day police went to his house again and searched everywhere. They did not find any cannabis but again there was £7000 of his wife money that police confiscated.
Then they took him to police station again, and showed him all his bank statements, since 3 years ago thousands of pound has been came and gone in his accounts.
So they asked about moneys and he said I have an exchange company and I also have the authorisation to do this job, however police said that you haven't paid your taxes and he answered that I did not know that I should pay tax for those money because I am just a dealer. Approximately he didn't pay for about £100,000 pounds.
Also he came to UK as an international student.
So what will be the penalty for growing 20 plants of cannabis with all these situations?