Blowers is accused of using his position as head of the organised crime unit to steal drugs from the police drug storage lock-up.
Mr Hamlin said Blowers had taken a portion of a large seizure of methamphetamine and used table salt to make up the weight to try to disguise the theft.
Blowers' alleged partner in crime is giving evidence against him and is subject to wide suppression orders.
Defence lawyer Arthur Fairley said in his opening address that Blowers strongly denied that he stole drugs or supplied the woman.
Blowers had loaned the woman money and "was most interested in getting it back", but it was not drug money.
"He will say he certainly did not give her methamphetamine or cannabis."
Supplying methamphetamine carries a maximum penalty of life imprisonment.
Blowers resigned shortly before he was arrested in April last year. He was investigated after one of his staff came forward with concerns.
The trial, before a jury and Justice Geoffrey Venning in the High Court at Whangarei is set down for two weeks.