|Prince Consort House|
Richard Slater, 48, of Spur Road, Orpington worked for Mentzendorff at their Thameside HQ in Prince Consort House, Albert Embankment, Lambeth.
The company was founded in London by Prussian-born Ludwig Mentzendorff in 1853 and received a royal warrant from Queen Victoria.
Slater was charged with committing unauthorised acts, with intent to impair the operation or hinder access to a computer, it's data or a programme in the company's eighth-floor office between June 22 and 30, 2012, contrary to the Computer Misuse Act.
He fought the case, but was convicted by a jury at Inner London Crown Court.