A lawyer has claimed that his clients in Moscow should not be prosecuted for violating US copyright law because they are not based in the country.

ElcomSoft, the software firm which employs Dmitri Sklyarov, has been charged with violating the Digital Millennium Copyright Act (DMCA).

A court has said that this was done by selling, and conspiring to sell, a program that allowed people using Adobe Systems' eBook Reader to copy and print digital books and transfer them to other computers.

ElcomSoft could face a fine of more than £1.58m ($2.25m) if convicted of violating the two year-old copyright act which bars the creation or distribution of technology that can be used to circumvent copyright protection.

The case is being held in the US and is not the first time that jurisdiction issues have become crucial to the outcome.

In what US District Court Judge Ronald Whyte considered a "novel argument" Joseph Burton, of the San Francisco firm of Duane Morris, which is representing ElcomSoft, said that since the company's entire operation occurred on the internet, the law did not apply because Congress did not authorise the DMCA to have control over events outside the US.

"Our position is that, regardless of where the website was, if the [alleged] criminal activity occurred on the internet, it's outside the jurisdiction [of the US]," he explained. Morris asked a judge on Monday to dismiss charges against ElcomSoft on this ground.

The US government originally jailed Sklyarov, the engineer who wrote the program, but released him and agreed to drop the charges in exchange for his testimony against his employer.

Sklyarov has said that he will also testify on behalf of his employer.