In total, seven warrants were executed simultaneously in the south and west of the county, including in Grays, Wickford, Brentwood and Canvey Island at 6.30am today (Wednesday 7 October).
They come as part of an investigation into the sale of drugs in Essex.
The nine people were arrested on suspicion of drugs and money laundering offences.
Officers also found a cannabis grow and equipment.
The investigation was one of those which came from Op Venetic – a major operation involving the cracking of a bespoke encrypted global communication service, exclusively used by criminals
EncroChat offered a secure mobile phone instant messaging service with 60,000 users worldwide and around 10,000 in the UK.
The primary use was for co-ordinating and planning criminal activities including the distribution of illicit commodities and money laundering.
Since 2016, international law enforcement agencies worked together to target EncroChat, and other encrypted criminal communications platforms, and earlier this year agencies in France and the Netherlands infiltrated the platform.
The intelligence gleaned through this was then shared via Europol to national law enforcement agencies.
Detective Inspector Steve Nelson, from the Kent and Essex Serious Crime Directorate, who led the warrants, said: “Drugs cause misery to our communities and we know their sale can also lead to other forms of crime, including burglaries, robberies, and violent crime.
“Where drugs are being sold, often there are also vulnerable people being exploited.
“We will always do everything we can to protect people and keep people safe and the warrants this morning will help do that.”