Sydney, Australia ? Police believe a nuclear reactor in southern Sydney was a possible target for an Islamic terror cell there, according to details of an Australian counterterror investigation released today.

Police previously questioned three terror suspects near Australia’s only nuclear reactor in December of last year, according to allegations made public today.

The three men stopped near the nuclear reactor were among 18 terror suspects arrested in Sydney and Melbourne last week and accused of plotting to carry out a “catastrophic” attack in Australia.

The men had an off-road motorbike and claimed they were there to ride, a police document said, noting that all three gave different versions of the day’s events to police.

Police inquiries revealed the lock of a gate to a reservoir of the reactor had recently been cut, the document said.