The trafficking involved illegal cannabis transported from Morocco to France.
A 48-year-old man, identified as M., received a suspended sentence of 30 months in addition to the six months of “firm” jail time, the Tribune de Genève reported.
He was arrested in October for using a financial company as a platform for laundering the illegal drug revenues.
A 38-year-old man identified as N., a former investment manager at HSBC in Geneva, got a two-year suspended sentence for playing a secondary role in the financial coverup.
Geneva justice authorities seized four million francs from a bank account and safe of the elder brother, the Tribune reported.
The money was carried across the Swiss border from France in plastic bags.
The pair, who cannot be identified because of Swiss privacy laws, have also been ordered to pay 50,000 francs in costs to the authorities.
The men were involved with a group of at least 17 other people who have been arrested by French police for smuggling pot from Morocco and selling it in France.
Swiss and French investigators cooperated in cracking the case under an operation code-named “Virus” begun last fall.