Queensland police spokesman Brian Swift
said further interviews would be conducted.
Police are hoping for an arrest in this matter and that be the objective of conducting the search yesterday [ Tuesday ], he
A major clue is reportedly a fingerprint found during an examination of a letter from one of the extortionists.
The suspects, a 61-year-old man and his
54-year-old wife, were among four people hospitalized during the extortion campaign which began earlier this year.
In February Herron Pharmaceuticals reported a threat which forced the nationwide recall of its headache tablets after a doctor and his
son were treated for strychnine poisoning.
SmithKline Beecham, makers of Panadol, Australia's top-selling painkiller, recalled its products from supermarket shelves after an extortionist sent letters of demand on May 31 and June 5.
One letter contained a demand for A $ 70, 000 (US $ 37, 800) cash to be left at Sydney's Circular Quay.A police sting to trap the suspects during the exchange collapsed when a passerby picked up the bag.
Then in October an envelope containing an empty Panadol packet with a note demanding $ 2 million was received.