Two juveniles were sent into 24 Canberra stores to purchase cigarettes between November and January, and nine stores sold the underage buyers tobacco products.

Attorney-General Simon Corbell said in a statement on Wednesday that 24 retailers were subject to the new compliance testing program, in which a "trained purchase assistant" under the age of 18 attempted to buy cigarettes under the supervision of an authorised officer.

Nine retailers were found to be non-compliant, in that they sold tobacco products to an underage person.

Mr Corbell said the Office of Regulatory Services was yet to prosecute the retailers in question.

He has also allayed concerns the government was encouraging underage people to buy cigarettes through their involvement in the program.

He said strict conditions were in place for the purchasing assistants, who were offered $100 gift vouchers once the testing is completed.

"Purchasing assistants undergo a comprehensive training program and are carefully supervised at all times during their inspections," Mr Corbell.

"In addition, all purchasing assistants must be non-smokers and display a commitment to seeing the reduction of the harmful effects of smoking on the population and of young people in particular."

More of the compliance testing will be carried out by the Office of Regulatory Services.