Two people have been questioned as part of an investigation into environmental crime in Lincolnshire.
The man and woman, both in their 20s, were held at an address in Long Sutton, between Kings Lynn and Spalding.
The arrests were part of a probe by the Environment Agency into catalytic converter theft across the county.
Lincolnshire Police assisted the Agency, recovering a large amount of cash and a machine to produce digital currency Bitcoin from the property during the operation earlier this month.
A number of converters were also removed from a van, a shed and a nearby storage unit by the police and officers from the Environment Agency's local enforcement and hazardous waste teams. The van was also seized.
Designed to remove harmful emissions from vehicle exhaust gases, catalytic converters contain precious metals, whose value has increased in recent times.
The pair have since been released pending further enquiries.
Yvonne Daly, an operations manager for the Environment Agency in Lincolnshire, said:
The storage of hazardous waste materials can harm the environment, blight communities and undermine the legitimate businesses that do follow the rules.
Our role is to protect the environment for people and wildlife, so we won't hesitate to take action against those who put it at risk. To businesses flouting the rules our message is clear: you won't get away with it.
Sgt Gareth Phillips, of Lincolnshire Police, said:
This was a successful joint operation between ourselves and a number of our partner agencies, which has resulted in the seizure of a number of suspected stolen items as well as a large quantity of cash.
We are still in the early stages of our investigation. We are working with the Environment Agency to see if any offences have taken place, and would urge anyone with any information to contact us on 101.
The operation took place on 7 September 2021.
Anyone who suspects illegal waste activity is reminded to report it to our 24-hour hotline by calling 0800 80 70 60, or anonymously contacting Crimestoppers on 0800 555 111.
