Drug squad inspectors arrested 11 men and one woman between December 2014 and September this year, cantonal police said in a news release issued on Thursday.
During investigations into a Nigerian cocaine trafficking network, police seized 4.6 kilograms of cocaine with a street value of around 500,000 francs, according to the release.
They also confiscated 33,000 francs and €9,700 in cash during several searches.
In an operation conducted in cooperation with police from the cantons of Jura, Zurich and Bern, as well as Lausanne city police, inspectors made the arrests in locations including Lausanne, Renens, Vevey, Territet, Chavornay, Delémont and Biel/Bienne, police said.
The arrested suspects, aged from 23 to 43, remain in custody.
Those arrested are originally from Nigeria, Ghana, Ivory Coast, Ethiopia, Eritrea and Poland, Vaud police said.
Based on the statements of the suspects, cocaine was illegally smuggled into Switzerland by “mules” who swallowed multiple “fingers” of cocaine, each containing ten grams of the drug.
They would retrieve the expelled sachets upon arriving at their destination, police said.
This “very risky procedure” allowed individual couriers to transport hundreds of grams of cocaine, originating from the Netherlands and Spain, in a discreet way.
Because the drugs trafficked were of a very high purity they could dilute them to boost profits from their illegal sale, the news release indicated.
Vaud police issued an X-ray photo showing how the drugs were dissimulated by the smugglers.
Various investigations into the case remain under way. These involve prosecutors from the cantons of Vaud and the Jura.