(some of the witness reports quoted above are from his investigation)
He wrote a report connecting the supreme truth cult to the 'explosion'. In 1995, Mr Mason claims he was informed by the chief council of the US Senate inquiry that the doomsday cult had an interest in Tesla weaponry, especially the electromagnetic earthquake-inducing technology.
The New York Times reported on the cult’s interest in the work of Tesla in an article published in January 1997. “The cult apparently sent a party of its members to the former Yugoslavia to study the work of Nikola Tesla, the discoverer of alternating current who toyed with the theory of seismic weapons before he died in 1943. At the Tesla Museum in Belgrade, the members seem to have reviewed Tesla’s thesis and other research papers concerning such [electromagnetic] weapons.
Link
Aums interest in weapons of mass destruction including sophisticated earthquake, weather and plasma weapons, were considered so serious, the US Senate Permanent Subcommittee on Investigations launched an investigation.
Their findings were published in the 100 page Nunn report in October 1995..
The Nunn report, in addition to outlining Aum’s large international membership and massive finances of over US$1 billion, also revealed the cult’s fascination for Tesla weapons.
The Senate report describes Aum’s visits to the New York based International Tesla Society (ITS), where they sought to obtain a number of his books, patents and papers.
A representative of the ITS told Senate investigators that Aum’s interest focused on Tesla’s experiments with "resonating frequencies," in connection with artificially "creating earthquakes." Significantly, the report also states that Tesla claimed "...with his technology he could ’split the world’ in two."
Link
They also researched and studied the Telsla coil at the Tesla museum, Belgrade.

Also they are thought to have uncovered Tesla's...
"high energy voltage transmission and on wave amplification, which Tesla asserted could be used to create seismological disturbances."
It is also believed the cult leader and his deputies made some powerful connections with high ranking officials in the Soviet Union.
Over several years the cult had deeply penetrated Russia’s military, intelligence, and political establishment. High level contacts included Oleg Lobov, a close confidante of Premier Boris Yeltsin. Lobov later became chairman of Russia’s Security Council - the nation’s highest decision making body.

Lobov, who was also the chairman of the Russia-Japan College, is believed to have been paid upwards of US$ 100 million for services rendered to Aum Shinrikyo.
Link
There are also conspiracies connecting them to a major earthquake in January 1995, which devastated the City of Kobe in Japan.
So to summarise.. A seriously rich cult obsessed on the end of the world, death and destruction, with major connections in the Soviet Union.. Research weapons of mass destruction.. Buy a remote sheep station in the Australian outback with vast uranium supplies.. bring two Soviet nuclear scientists and mining equipment.. An unexplained 'explosion' occurs which causes a seismic event registered on the Richter scale and they later committed a horrific attack on a packed subway..
Did the supreme truth cult really build and test a weapon of mass destruction in the Australian outback in 1993?
From Bill Bryson's In a Sunburned Country..
"This is a country . . . so vast and empty that a band of amateur enthusiasts could conceivably set off the world's first nongovernmental atomic bomb on its mainland and almost four years would pass before anyone noticed."
A credit also has to go to Mysterious Universe who covered this story in their podcast episode 618





