The drugs had a street value of up to A$2 million.
Prince, an ordained minister and head of the Oasis of Grace International Church, has consistently claimed a Kenyan woman called "Mummy Rose" gave her the backpacks to sell in churches in Australia.
She claimed the bags were made by African women, AAP reported.
However, Mr Rice said her claim didn't stack up.
"The bags were commercially produced bags that might be made anywhere. In fact, they were tagged as having been made in China," he said.
Also, the cardboard used to pack the drugs was Cambodian, meaning the backpacks were either not obtained in Kenya at all, or were packed with drugs during the four days she spent in Cambodia on her return trip, Mr Rice said.
A drug expert is expected to testify that the heroin in the bags had a Southeast Asian chemical profile.
Prince is charged with importing a commercial quantity of a border-controlled substance.
The trial continues.