As the music fades a voice-over chimes in deep, sombre tones: 'This sleazy apartment house, our driver duly points a finger towards the building we're parked outside, 'was the final resting-place of the screen's most famous Dracula. Bela Lugosi died here in 1956, flat broke and undergoing treatment for drug addiction.'

Bela's final curtain was one of many during an awesome afternoon of deaths by shooting, stabbing, OD-ing, falling from tall buildings, even an auto-erotic asphyxiation (hats off – but rope and handcuffs on – to Albert Dekker); and of visits to the sites of orgies, drug busts, drink busts, and horrific accidents of all kinds, provided with impeccable style and absolutely no taste by the fun-loving ghouls of Grave Line Tours.

Three times daily their hearse ferries its sleaze-seeking passengers on a two-and-a-half-hour tour of some of Hollywood's seamiest addresses. The city has something lusciously sinful, outrageously wicked, or at least grimly entertaining on every block and all of it is smeared with the blood of Big Names, which effectively turns the appetising array of gore into public property, making Hollywood not only one of the most delectably eerie places on the planet – but also one of the most fun to explore.

But you can read both volumes of 'Hollywood Babylon' until you're turning blue, and find that neither are much help when actually looking for the precise locations of the sordid happenings. This is where Grave Line Tours come to the rescue. They take their name, with a playful plagiaristic flourish, from the cringeful Starline Tours – an institution since before the Ark (or talkies, whichever came first) – who drag their over-charged customers on a dazzle-lacking tour of 'Star Homes' (ie the gates of Stars' homes where, if you're lucky, you'll see one of the Stars' guard dogs) on which everything is as tinselly as Hollywood is supposed to be but isn't, and as genuine as the plastic neo-classical sculptures which line the driveways of Beverly Hills.

Grave Line Tours are different. Very different. The company president – and he wears his mourning suit proudly – is called Greg. When I met him he didn't shake hands because he was halfway through a BLT and the latest issue of the National Enquirer. This convinced me that he was not slick. Strange but true, Greg is a qualified mortician from Kansas who felt the call of the west after his dying mother beckoned each of her offspring to her bedside for final goodbye. To Greg she just called: 'Greg, you're weird, you've always been weird . . .'

Besides the hearse, fitted with plush aircraft seats, the Grave Line 'service' includes a driver/'sight-seeing counsellor' attired in full funeral regalia, whilst the 'mourners' themselves are each given a complementary Calla lily (the traditional flower of death) and maps of Hollywood's most star-studded cemeteries.

Once under way, everything hinges on the taped commentary, complete with music and sound effects (the noise of people falling from high windows is particularly impressive). But the dialogue itself is the strong point, and while cloaked in the blackest of black humour it remains startlingly candid and accurate.

The Grave Liners pride themselves on their research, both the comparatively straightforward kind – hours spent scrutinising death certificates in the various LA morgues – and the more bizarre: Greg working under cover at the famous Forest Lawn cemetery, ostensibly selling tomb plots over the phone but also gaining illicit access to the otherwise carefully guarded files.

And the pace is intense. From the first few minutes obituaries are flying in every direction: 'In this seedy motel ...', Janis Joplin bowed out; 'In this ordinary car-port ...', Sal Mineo was knifed to death and the gasoline stains seem to turn blood-red before your very eyes; 'It was in this liquor store . . .', John Belushi flipped his lid with the owner and later expired in a bungalow of the neighbouring Chateau Marmont hotel, coincidentally 'across the road from what used to be Schwab's Drugstore and where Harold Arlen composed "Over The Rainbow" on the pavement.'

And there's more and more and more and then ... we head for the hills. The Hills are one of the nicest things about Hollywood. Suddenly you're off the traffic-laden boulevards and into wild and rugged countryside lined by tortuous tracks leading to a rambling collection of odd homes. The hearse chugs up a gradient of one-in-four and we strain our necks towards Beverly Hills to glimpse the remains of Rudolph Valentino's 'Falcon Lair' mansion, then strain still further to see the house that staged the Manson killings, and, as the vehicle rolls back down the slope, have our brains disengaged from Mansonic thoughts by ' . . . we are now following the exact route taken by Montgomery Clift on a fateful night. . .' That was the night MC wrapped his car around a telegraph pole and mangled half his face. We pause significantly by a telegraph pole. 'At this very spot . . .' Tremendous.

Other things stick in the mind which are noted merely as we pass by: the grotty hotel occupied by Doors' singer Jim Morrison with Jim's Room' still graffitied beneath the relevant window; numerous ex-homes of Marilyn Monroe and the building where she first posed nude; the scene of the party where Errol gave birth to the 'in like Flynn legend'; where Superman got stiffed by his own speeding bullet.

Happily, the Grave Line conception of gore spans the decades and acknowledges outstanding achievement in all fields of dishonest endeavour. Anything of sufficient juice gets mentioned be it from films, music or political scandal (although the tour has its less thrilling segments: 'Over there,' we're told hesitantly, 'that's Lucille Ball's house.').

Yet much of the fun is in the 'grief' shared with one's fellow mourners and the fiendish relish of the counsellor himself. As I'm leaving the hearse at the end of the tour, a passer-by notes the absence of a coffin and yells 'Where's the body?' 'We lost it,' Greg confesses with a manic grin, 'it's been one of those days.'.