Lindsay Sandiford, 55, covered her face as she was taken out to face the media at a press conference in Kuta, a holiday town on the Indonesian island.
She was pictured sitting at a table surrounded by packages wrapped up in brown tape as a customs official cut them open with a knife.
Wearing an orange prison T-shirt, she was also photographed flanked by armed officers wearing black masks.
Sandiford was stopped with the 4.7kg haul in a suitcase as she arrived in at Bali’s Ngurah Rai International Airport on a Thai Airways flight from Bangkok in Thailand on May 19, according to customs official Made Wijaya.
Three other Britons and an Indian national were believed to be the intended recipients and are being questioned.
Indonesia has extremely strict drug laws and convicted smugglers are executed. More than 140 people are on death row, a third of them foreigners.
A Foreign Office spokesman said: “We are aware of the arrest in Bali, and we stand ready to provide consular assistance.”