JUST as some people are endlessly fascinated by the question of who killed JFK, the murder of the Romanovs evokes an interest bordering on obsession. The truth about the tsar's family could not be told during the communist regime, and remains even now politically charged. It has all the components of a modern myth - the violence, the distant glitter of royalty, the teasing possibility of survivors - but now that most of the facts are available, the story seems more, rather than less, strange, with enough outlandish detail to snag any imagination.

In the summer of 1918, the tsar's family, with a few of their retinue, were under arrest in the Siberian town of Ekaterinberg. The White forces were so close that their artillery could be heard rumbling in the distance; on 16 July Yakov Yurovsky, the commander of the "House of Special Purpose", received from Moscow the order of execution.

It all went wrong from the start. At midnight, 11 people were awakened and assembled in a small basement room: the former tsar, Nicholas, aged 50, and his wife Alexandra; their four daughters, Olga (22), Tatiana (21), Marie (19) and Anastasia (17); the 13-year-old tsarevich, Alexei, so crippled with the haemophilia inherited through his great-grandmother, Victoria, that he had to be carried by his father. The family's doctor, their cook, Nicholas's valet and Alexandra's maid Demidova came too. Demidova clutched a small pillow which turned out to be a hiding-place for some of the many jewels the family had secreted about them; Anastasia clutched her King Charles spaniel.

They were lined up as if for a photograph. Yurovsky called in a squad of 11 men, each briefed to shoot a designated victim cleanly through the heart. In a room no more than 12 feet square, this should not have been too difficult, but when the bullets began to ricochet off the chests of the daughters, the soldiers became hysterical, using bayonets and rifle butts to finish off the victims in a ferocious bloodbath.

The truck was late. There were no stretchers for the bodies. When finally the grisly load was jolting along muddy forest tracks, looking for the abandoned mineshafts chosen for the disposal of the corpses, a party of factory workers from the town turned up, tipped off by friends. The truck got stuck. Yurovsky ordered the bodies to be unloaded onto carts; looting began.

When the macabre procession reached its destination, the bodies were stripped and the mystery of the ricocheting bullets was solved: each of the grand duchesses was wearing a corset so tightly studded with diamonds sewn into the fabric that it had acted as armour; the empress was wearing a belt made up entirely of pearls sewn into linen. The recovered diamonds weighed 18 pounds.

At last the naked, bayoneted bodies were thrown into a deep mineshaft, hand grenades chucked after them in an attempt to collapse the pit. The clothing was burnt; the site cleared. Yurovsky must have thought his terrible task was done.

Only eight days later, the White forces captured Ekaterinberg. It was not for some months that a White investigator, Nicholas Sokolov, found a place in the forest which showed signs of wheels, fires, hooves. His men collected dozens of objects from the area: charred jewellery and corset- bones, belt buckles, glasses and false teeth, one human finger, the decomposed corpse of a King Charles spaniel. But, although the mineshafts were pumped out, there were no bodies. Sokolov concluded that the corpses had been burnt.

For decades, that is all anyone knew, and all we might have known but for the curiosity of Alexander Avdonin, a native of Ekaterinberg (by then renamed Sverdlovsk), and a Moscow film-maker called Geli Ryabov. Over the years, in deadly secrecy - the subject was forbidden - they gathered testimony and searched for the missing bodies. A lucky break brought them into contact with the son of Yakov Yurovsky, who gave Ryabov a copy of his father's secret report on the executions - he wanted to atone for the "most horrible page" in his father's life - and a new story was revealed.

When Yurovsky got back to Ekaterinberg after the murders, the town was already humming with rumours of the whereabouts of the bodies: the soldiers had talked. Yurovsky knew the corpses would have to be moved (the White Army was close), and there followed another grotesque saga of midnight exhumation, bodies lurching on carts through the mired forest, a shallow common grave for all the bodies except two - those of Alexei and one of the daughters - whose remains were burnt.

It was at this second site that, in May of 1979, Avdonin and Ryabov conducted a clandestine excavation. They took away three skulls, but after a year of frustrated attempts at secret forensic testing, and still afraid of the repercussions, they returned the skulls, in a wooden box, to the grave. And there they were found, with the rest of the now scarred, charred and muddled bones, in 1991 when - the day after Boris Yeltsin's inauguration in Moscow - an official excavation took place.

The rest - from the forensic processes to the political and religious sensitivities about the burial of the remains - is now painstakingly documented. But given that we do have such a complete picture, it seems odd that in the spate of recent publishing no single definitive account has emerged.

Robert K Massie's The Romanovs: The Final Chapter begins at a cracking pace, plunging straight in to the execution, the bungled attempts to dispose of the corpses, the problem of secrecy, the delayed disclosure of the facts. The opening of his book is enthralling, written with a sense of drama that does nothing to affect its clarity. But as soon as he starts on the forensics research, he spins off into a double helix of scientific machinations and jealousies. Massie is more interested in all this than he could persuade me to be, and an account involving pieces of bone flown across the Atlantic, a blood-encrusted handkerchief from a museum in Japan, and the information that Michael Jackson offered a million dollars for the skeleton of the Elephant Man, verges on the Clouseau-esque.

Massie also takes the curious decision to devote many pages to Anna Anderson, the woman who claimed to be Anastasia, and other impostors. Why these variously bogus and implausible "claimants" were ever taken seriously is another mystery, but the skill of great con-artists has powerful appeal. And those who want exhaustive information about the surviving Romanovs' claims to the "throne" need look no further.

Steinberg and Khrustalev's The Fall of the Romanovs has more bite. It uses documents of all kinds - the emperor's diary, simple as a schoolboy's, the empress's bizarre and passionate letters (written in English), the girls' cheery, childish correspondence, official telegrams and orders - in a sort of collage. There are unforgettable quotes here, and they reveal, with terrible clarity, this man of limited intelligence, for 23 years absolute ruler of a sixth of the world, and his domineering wife, whose political acumen makes Marie-Antoinette look street-wise. They believed in god-given autocracy, and that the Russian people were "childish". "Russia loves to feel [the] whip," Alexandra wrote, "it's their nature - tender love & then the iron hand". The authors hardly needed a chapter entitled "Nicholas and Alexandra: An Intellectual Portrait" when they had this sentence from Nicholas's diary: "A white sea of soldiers in a pretty country on a warm summer day - nothing can be finer for me, except a squadron of large ships". Or Alexandra, begging her "beloved, precious angel" to play the groznyi tsar: "Ah my Love ... show to all, that you are the Master & your will shall be obeyed - the time of great indulgence & gentleness is over - now comes yr reign of Will & power, & they shall be made to bow down before you ..."

It is easy to see why Nicholas's ministers kept him away from Alexandra when they were desperately persuading him to abdicate, early in 1917. He did resist her, from a distance, even signing himself "ever your very own poor little huzy with a tiny will". At this crucial moment, all her children had a serious case of measles, and Alexandra sat, literally in the dark, in a shuttered sickroom, firing off responses to the growing tumult muddled with details of the children's symptoms. On the day of abdication, she knew Nicholas had to sign "some paper of theirs, constitution or some such horror", but was convinced that "If you are forced into concessions - you are never required to keep them". And later: "Two currents - Duma & revolutionists - two snakes who I hope will eat off each others heads ... they made too big a fire & how to put it out now. - The children lie quite in the dark, Baby [Alexei] lies with them ... - Olga 37.7, T 38.9 & ear begins to ache..."

There is much else, too, in this intriguing and unconventional book. The personal tone of the letters and diaries evoke a certain human pity, but also a revulsion at the mingling of grave events and babytalk: these people, one feels, would make revolutionaries of us all.

Politics meets the world of interiors in Peter Kurth's lavish Tsar: The Lost World of Nicholas and Alexandra, with as many frilled parasols, troikas, shooting parties and Faberge eggs as anyone could want. But the text is not as desultory as its presentation would suggest: there's an amusing description of Alexandra's early years in her adopted country, where the St Petersburg ladies mocked her prudish German ways and her ghastly English taste: she sent for her furniture from Maples, and surrounded herself in "a sea of chintz". As the book goes on, the family snaps and grand portraits are interspersed with horrifying shots of piled corpses at the front, of the bullet-shattered basement room in Ekaterinberg. Perhaps it says something about this family, and this story, that even their gruesome death ends up in a glossy book. We even discover that the sole survivor of the massacre at Ekaterinberg was Alexei's dog - a spaniel called Joy.

'The Romanovs: The Final Chapter' by Robert K Massie, Cape pounds 17.99

'The Fall of the Romanovs' by Mark D Steinberg & Vladimir M Khrustalev, Yale pounds 18.50

'Tsar: The Lost World of Nicholas and Alexandra' by Peter Kurth, Little, Brown pounds 35

'Royal Russia: The Private Albums of the Russian Imperial Family', Smith Gryphon pounds 17.99