Officers carried out warrants at three addresses in the early hours of Tuesday morning, 5 December, following an extensive investigation into the conspiracy to supply class A drugs in Gwent.
Two men – aged 32 and 56 both from the Newport area – were arrested at the properties and remain in police custody.
A further two men – aged 32 and 45 also from the Newport area – were arrested following the warrants in connection with the investigation.
DI Ian Bartholomew, the senior investigating officer in the case said: “The warrants today relate to Operation Mayland, an investigation into a serious organised crime group conspiring to supply class A drugs.
“The operation was led by the organised crime unit and focused on the arrest of two men, who are believed to be highly involved in the supply of class A drugs – cocaine and heroin – within our community.
“Drug supply and its associated criminality has an extremely detrimental impact on our communities, and sometimes further afield. It goes beyond those exploited to sell them and the vulnerable people addicted to them. It affects everyone from law-abiding citizens to public services and businesses.
“Drug investigations and warrants like this help to disrupt these offenders and sends the message that serious and organised crime groups are not welcome in our communities.”