In early 1990, acting on the basis of information provided by a witness in another investigation, South Australian police began searching Myponga Reservoir on the Fleurieu Peninsula. They were searching for the bodies of the Beaumont children and also for the bodies of Kirste Gordon and Joanne Ratcliffe. Nothing was found.
The search was based on the evidence of a witness known as "Mr B". A witness for the committal hearing of Bevan Spencer von Einem for the murders of Alan Barnes and Mark Langley, Mr B made a statement to Sydney police in September 1989 that implicated von Einem in the disappearance of the Beaumont children and the abduction at Adelaide Oval.
When the search of the Myponga Reservoir began, Mr B's evidence had not yet been made public. What he'd told police was that von Einem had abducted the Beaumont children, had "connected them up" 19 and "did some brilliant surgery on them" 19 and that one had died. The bodies had been dumped at Moana or Myponga, south of Adelaide. Mr B also said: "He also told me he picked up two children at the football." 19
Police assumed that "the football" was a reference to the disappearance of Joanne Ratcliffe and Kirste Gordon. Based on deduction or further evidence, police concluded that Myponga Reservoir was where von Einem had dumped the bodies – if Mr B was telling the truth about what von Einem had said, and if von Einem in turn had been telling the truth to Mr B.
In an operation organised by the major crime squad, police divers began searching the reservoir on 2 February 1990. Mr B’s evidence had not been made public and police told media that they were searching for a safe. An opened safe was found, as was a large quantity of stolen goods, but no remains were found.
Within a few days there was open speculation, possibily based on leaks to the press, that the search was for the remains of the Beaumont chlidren. Police admitted on 8 February that they were searching for a body or bodies but would not comment further.
The search was soon called off, with the police diving squad leaving to train in sink holes near Mt Gambier. A police spokesman explained that "black water" training in specialist diving techniques had been planned for the squad for some time. The particular challenges of searching the Myponga Reservoir meant that this training would be doubly beneficial.
The search of the reservoir presented some unusual diving challenges. Fine silt in the water reduced visibility to almost zero. Tonnes of silt would have accumulated over the 24 years since 1966, which could have buried any remains. Marine life could have scattered remains over a wide area. Finally, the depth of the reservoir at the dam wall reached 100 metres deep in places, which limited a diver's time at the bottom and make it necessary for divers to undergo lengthy decompression procedures.
On the upside, forensic experts said that the cold water at the bottom of the reservoir meant that any skeletal remains would have been preserved.
A second search of the reservoir began in late February, with police still refusing to confirm that the search was for the remains of the missing children. The search of the reservoir was done sporadically due to scheduling constraints, but after a short break it was rumoured that the search would begin again on 2 March in deeper parts of the reservoir. It was also rumoured that police had received evidence that the children’s bodies had been dumped from the wall of the reservoir. Mr Beaumont was asked for his opinion about the search and said: "I don’t know what to think. I only know as much as you, and any other man in the street, knows about this search." 24
On 17 March, the Adelaide newspapers were able to report the evidence that had been given by Mr B at the von Einem committal hearing, confirming the previous speculation about the reason for the search. The search of the reservoir had been suspended again but it was understood that it hadn't been completed and would resume. Naturally, a local "psychic" claimed to be able to show police where the bodies were buried near the reservoir, but her insights were worthless. 25
The search resumed again on 3 April. A week later, hoaxers began circulating rumours that the remains of the children had been found in a suitcase at the bottom of the reservoir. Newspapers often rely on tip-offs and the Adelaide Advertiser later said that they'd received several anonymous phone calls trying to spread the story. By 17 April a spokesman for the major crime squad had confirmed that there was nothing whatsoever in the rumour.
On 11 May, with the search completed, police finally admitted that they’d been searching for the Beaumont children. Eight divers had been involved and the search had taken eight days in total. However, Superintendent Trevor Johnson, officer-in-charge of the major crime squad, confirmed that the search had found nothing. It was yet another false lead.
Other false leads: