BRISBANE, Australia (AP) _ Anonymous threats to plant poisoned cookies in stores prompted a leading food company today to recall its cookies from four Australian states.

Arnotts, a firm owned by New Jersey-based Campbell Soup Co., pulled cookies off the grocery shelves in New South Wales, Queensland, South Australia and Victoria.

Six people have received packages containing threatening letters and boxes of poisoned Arnotts cookies, said detective Superintendent Ron Pickering. Authorities said the pesticide used to contaminate the cream-filled cookies was toxic enough to kill a small child if just one cookie was eaten.

One letter went to a Brisbane newspaper, but authorities did not reveal who received the others.

Police said the letters included a demand that a New South Wales police officer undergo a lie detector test in connection with an investigation into the murder of bookie Peter George Wade and his wife in 1991. Police said they would not grant the demand.

In 1993, the Brisbane Supreme Court found Ronald Henry Thomas guilty of the murders and sentenced him to life imprisonment. The letters claim that police framed Thomas.

Unless the demand is met by Monday, the letter says, poisoned packets of Arnotts cookies will be placed on supermarket shelves in New South Wales and Queensland.

Chris Roberts, chief executive of Arnotts, said the cost of the recall could run into ``millions of dollars.''