Officers allege that Brian Howes, 43, from Middlesbrough, and Kerry Ann Shanks, 28, from Bo’ness, created a “one-stop shop” for drugs producers.
They said the pair sold enough chemicals to make 1,400lb of the drug with a street value of £6.4m ($12.6m). Extradition proceedings have begun at Edinburgh Sheriff Court.
Their arrest follows a two-year investigation nicknamed Operation Red Dragon into production of the deadly Class A drug involving three UK forces – Central Scotland Police, Cleveland Police and Scotland Yard.
These officers were working in conjunction with the US Drug Enforcement Agency (DEA) and the Serious Organised Crime Agency (Soca) as well as other law enforcement agencies in the US.
Officers from Central Scotland Police made the arrests in Bo’ness, near Falkirk, on Tuesday.
The move followed an indictment handed down by a grand jury in Arizona which alleges that the couple sold chemicals through their website – including red phosphorus and iodine – which are used to manufacture methamphetamine.
US District Attorney for Arizona, Paul Charlton, said Mr Howes and Ms Shanks were suspected of supplying a global network of meth labs in the US, Europe, Australia and New Zealand and other countries dating back to 2004.
A conviction for unlawful importation and distribution of regulated chemicals such as red phosphorus carries a maximum penalty of 20 years, a $250,000 (£128,268) fine or both.
Mr Charlton added that the couple’s website came to the attention of the US authorities after investigators in Arizona uncovered numerous clandestine methamphetamine – crystal meth – labs in the US state which purchased their chemicals through the site.