By Alfred Hermida BBC News Online technology correspondent

Dangers lurks in the shadows of Doom 3's underworld

The latest instalment in the bestselling series, known for its intense action and realistic violence, comes with an 18 rating.

Developers id Software say it is the most frightening and gripping gaming experience ever created.

Its release has also been marred by widespread online piracy of the game.

Sense of dread

Doom 3 is the second follow-up to the 1994 first-person shooting classic. It is one of the big titles of the year, the gaming equivalent of the release of a new Harry Potter book.

The original Doom is credited with introducing 3D graphics, making gaming a much more realistic experience. So there is a great deal of expectation surrounding the latest version.

In it, gamers play the part of a marine on Mars, facing a horde of demons released from hell by scientific experiments.

Doom 3 is a game suitable for an adult audience, marketed appropriately to adult consumers who make their own choice whether to purchase Tim Ponting, Activision Reaping the profits of Doom

Doom 3 has been four years in the making and is estimated to have cost around $15m (�8.3m).

It has been widely praised for its atmospheric graphics and sound, which create a pervasive sense of dread about what might jump out of the dark.

"There has been huge anticipation for Doom 3 worldwide," said Tim Ponting, Head of European Corporate Communications at Activision.

"We expect demand to be extremely high," he told BBC News Online, adding that the company was very pleased with sales in North America in its first week of release there.

Controversy over violence

The UK launch comes at a time when there is some disquiet about extreme violence in games and the ease with which under-18s can obtain copies.

Two weeks ago, the parents of a murdered teenager blamed his killer's obsession with a violent game for their son's death.

Detectives investigating the murder rejected any link with the game, saying the motive was robbery.

Remembering the first Doom

An earlier version of Doom was blamed for triggering a violent response.

After the Columbine school killings, it was claimed that teenage killers Eric Harris and Dylan Klebold were influenced by violent games, including Doom.

Publishers Activision said they were not worried that the recent media coverage about violent games would affect sales.

"Doom 3 is a game suitable for an adult audience, marketed appropriately to adult consumers who make their own choice whether to purchase," said Mr Ponting.

"There is a robust, well proven regulatory framework in place and Doom 3 has been fully approved for distribution in the UK with a BBFC rating of 18.

"There is nothing to debate here," he insisted.

First person action

The game's release has also been overshadowed by widespread piracy.

Thousand of illegal copies of the game have been downloaded in the past two weeks via file-sharing networks and newsgroups, following the game's appearance in some US shops.

The potential losses could run into millions.

The 1994 original, by Texas-based developers id Software, was a ground-breaking game.

Doom drew players into a three-dimensional virtual world where they had to battle monsters.

It helped to establish the concept of the first-person shooter, in which gamers see the world through the perspective of the lead character.

The PC version of the game went on sale in the US a week ago and a version for Microsoft's Xbox is due later in the year.

The Doom franchise has already grossed more than $100m (�55m).