Douglas Adams voiced the character Agrajag before his death in 2001

The text adventure will appear on the station's website and was described by the late Adams as "the first game to move beyond being 'user friendly'".

"It's actually 'user insulting' and because it lies to you as well it's also 'user mendacious,'" he said.

The final three Hitchhikers adaptations will be broadcast from 21 September.

New illustrations

The game, originally published in 1984, contains rare writing by the author and is - in Adams' words - "full of extraordinary ways of dying".

Users can play a number of characters from the book, collect over 40 items and read dozens of Hitchhiker's Guide entries.

The new version of the game will be illustrated by Rod Lord, who won a BAFTA for his graphics for the original Hitchhiker TV series.

Radio listeners will also be invited to submit their own illustrations.

Many of the original TV cast will reprise their Hitchhiker roles

The final three books in the Hitchhiker's series - Life, The Universe And Everything, So Long And Thanks For All The Fish and Mostly Harmless - have been adapted for the six-week Radio 4 series.

A number of actors from the BBC television series are reprising their original roles, including Simon Jones as Arthur Dent and Mark Wing-Davey as Zaphod Beeblebrox.

Adams' own voice is being used to play Agrajag, a role he recorded before his death.