Leon Reid, a bronze medalist at the 2018 Commonwealth Games, has been charged with drugs, possession of firearms and money-laundering offences, alongside five other men.
Reid, 26, has been charged with conspiracy to supply cocaine, permitting premises to be used in the production of crack cocaine, concealing criminal property, and acquiring criminal property.
"Items including six encrypted phones, a Glock 19 handgun, a carbine conversion kit, a silencer, an extended magazine, ammunition, eight kilos of cocaine, four kilos of crystal MDMA, 3,000 ecstasy tablets, a hydraulic press, and £434,000 cash have been seized during the investigation," the South West regional organised crime unit said in a statement.
"The men were all arrested last year as part of Operation Venetic, the UK law enforcement response to the take down of encrypted global communications service EncroChat."
In a statement, Ireland Athletics said: "Athletics Ireland has been notified today that an Irish international athlete, Leon Reid has been charged with a criminal offence outside the jurisdiction of Ireland.
"Athletics Ireland cannot comment further until all elements of due process have been completed."
The Northern Ireland sprinter won bronze in the 2018 Commonwealth Games in the Gold Coast with a time of 20.55 seconds becoming the countries' first Commonwealth Games track medal winner in 28 years.