Authorities in France and Switzerland have arrested 20 people, including Florence Lamblin, the deputy mayor of a Paris district, on suspicion of laundering some 40 million euros of drug money.
Florence Lamblin resigned from her post on Saturday but denies any involvement.
Nine suspects, including her, have been charged with offences ranging from money laundering to drug trafficking.
The arrests are part of an investigation into the smuggling of cannabis from Morocco to Paris.
A French police source told the AFP news agency that this case was one of the biggest of its kind.
A lawyer for Florence Lamblin, an elected Green Party member and deputy mayor of Paris’ 13th Arrondissement, told the media that she has no involvement and the charges against her were down to “judicial error”.
Reports say that around 400,000 euros in cash was found by police during house searches and millions more has been uncovered in safety deposit boxes and bank accounts.
In total, 17 people were arrested in France and three in Switzerland.
Of the nine people already charged in France, eight were freed on bail of between 80,000 and one million euros and the ninth was kept in custody on suspicion of drugs offences.
Press reports in Switzerland said the three suspects there were brothers of Moroccan origin. Authorities told AFP that two men remained in custody and one had been released on bail.