The US State Department has finally agreed to let Russian software developers into the country for the trial of Elcomsoft, the company alleged to have broken a new digital copyright law.

The department had put the brakes on the trial by refusing visas to Alex Katalov, the chief executive of the Moscow-based software company, and Dmitry Sklyarov, one of its programmers.

But according to the San Jose Mercury News, a pretrial hearing was told that the Immigration and Naturalisation Service had approved special visas for Katalov and Sklyarov.

Elcomsoft is the first company charged with criminal violation of the 1998 Digital Millennium Copyright Act.

It has been accused of providing the means to "crack" Adobe's eBook reader that allows publishers to sell books online in a format that prevents copying or transferring content between users.

Sklyarov, who developed the algorithm upon which the Elcomsoft program is based, originally was charged along with his employer. But federal prosecutors have agreed to drop charges against him once the case is completed.