Muriel McKay and her husband, Alick McKay, were born and raised in Adelaide, South Australia. By 1969, after moving to London for her husband's job as a newspaper executive for Rupert Murdoch's News Limited, they lived in St Mary's House on Arthur Road in Wimbledon. Their 2 adult children, Ian McKay and Diane Dyer, also lived in the UK.
On 29th December 1969, assailants broke into the home and abducted Muriel while her husband was at work. Returning home at 7:45pm, and finding the front door unlocked, the telephone ripped from the wall, the content of his wife's handbag scattered on the stairs, and the house empty, Alick McKay reported her missing at 8pm. The attack was especially troubling given that jewellery had been stolen in a burglary incident 3 months earlier, and Muriel had becoming increasingly careful of her personal safety.
Police soon arrived and it quickly became a kidnapping case after investigators found items that were foreign to the house: Elastoplast, twine, a newspaper, and a billhook. After the phone was repaired, at 1am, a caller identifying himself as "M3" contacted the house and demanded a £1 million ransom. Over the next 40 days, M3 made 18 more calls, demanding to speak to either Alick, Ian, or Diane, and sent 3 letters demanding the money while repeatedly threatening to kill Muriel. 5 letters written by Muriel and pleading for compliance were enclosed as "proof" that she was alive, as were 3 pieces cut from her clothing.
However, 2 successive attempts to deliver half of the money were unsuccessful. The first one, on 1st February 1970, on the A10 was abandoned due to a large police presence in the area. A second attempt was then made on 6th February. Following M3's detailed instructions, 2 disguised police officers placed £500,000 in 2 suitcases and left them at a telephone box in Church Street, Edmonton. The police conducted surveillance in the area and noticed that a blue Volvo sedan with a broken tail light, registration XGO994G, and with a single occupant, slowly passed the box 4 times between 8pm and 10:30pm. At 10:47pm it passed again, this time carrying 2 men. However, a local couple noticed the suitcases and became concerned. The woman kept watching while her husband reported the cases to the police, who were unaware of the drop off and took them to the local station.
The investigation then shifted to the Volvo, registered in the name of a man from Rooks Farm near Stocking Pelham, Hertfordshire. Reviewing previous reports, they noted that some witnesses had also described seeing a dark coloured Volvo sedan driving near Arthur Road in the hours before the disappearance was reported, and another one reporting it as parked in the McKay driveway around 6pm. Police also noticed it acting suspiciously at the first drop off attempt but had assumed it was either undercover police or local. The farm, which covered 11 acres and was considerably run down, was then raided by police on 7th February at 8am. The owners of the farm were Arthur Hosein, 34, and his German wife, who also lived with his youngest sibling, Nizamodeen, 22, who had worked there as a labourer since August. A notebook was found inside with torn pages that matched the tear patterns in Muriel's letters. Further, twine and a matching roll of tape were found, and the billhook was revealed as belonging to a neighbour. The brothers' physical descriptions also matched those of the men seen in the Volvo, and Arthur's fingerprints also matched those found in the ransom letters and a newspaper found in the McKay house. Similarly, Nizamodeen's voice matched that of recordings of M3 when he was tested on a telephone. However, no trace of Muriel was found at the farm, even after it was searched for several weeks.
Based on the evidence, the pair were arrested and sent to trial on 14th September 1970, with the prosecution led by Peter Rawlinson. At the trial it was learned that Arthur, a tailor in Hackney, was experiencing financial difficulty after buying the farm in May 1968. The farm, originally established in the 17th century, was used to raise cattle, pigs and chickens. The Hoseins decided to kidnap Anna Murdoch after watching David Frost interview her husband about his recent purchase of News of the World and The Sun on 30th October on television. The confusion arose when the Hoseins followed Murdoch's chauffeured Rolls Royce to the house in Arthur Road, which they assumed to be the residence of the Murdochs, but it was actually the McKays. Unknown to the brothers. Murdoch had loaned the car to his deputy for a few weeks while he and his wife were in Australia.
Throughout the case, each brother tried to put the blame on the other, although it was soon determined that the older brother was the more dominant of the 2. The brothers were convicted on the charges of murder, blackmail and kidnap at the Old Bailey on 6th October 1970. Giving them life sentences, plus 25 years in Arthur's case, and 15 in Nizamodeen's for kidnapping, the trial judge, Justice Shaw, said their "conduct was cold blooded and abominable". Despite investigation, it was never established what happened to Muriel's remains, though there was speculation that the Hoseins had fed them to their guard dogs or pigs.
The brothers were sent to Winson Green Prison where they appealed their sentence in March 1971. In November 1987 and September 1994, Arthur unsuccessfully applied for parole. Arthur died in 2009 in prison, whereas Nizamodeen served 20 years and was deported to Trinidad after his release.
The nature of the case led to widespread media coverage alongside numerous hoaxes and prank letters and calls to the McKay home. Psychic Gerald Croiset, who was involved in a number of famous missing persons cases, also became involved. Based on its notoriety, likeliness of the brothers were displayed in Chamber of Horrors in Madame Tussauds alongside that of living serial killers, Donald Neilson and Graham Young.