Detectives probing alleged drug dealing and money laundering offences in west Cumbria have released all nine of those arrested under investigation.
Cumbria Constabulary say inquiries are currently ongoing.
It is understood that a number of those arrested are employed at the Sellafield site, however, no arrests or drugs have been found at Sellafield.
An earlier statement from Sellafield Ltd said: “We can confirm we are assisting Cumbria Constabulary with an ongoing investigation into drug use and distribution.
“This investigation is not focused on Sellafield. For legal reasons, we are unable to comment on individual cases.
“We have a strict policy regarding the misuse of drugs and alcohol. All of our employees and supply chain partners must comply with this.”
It is understood that of the nine people arrested, one is a Sellafield Ltd employee. This employee was arrested at home, not on site, Cumbria Crack understands.