New South Wales police, investigating an extortion threat to food company Masterfoods, say that a contaminant found in a Snickers bar is like pest poison.

Following the receipt of a letter and a contaminated Snickers bar by Masterfoods, an interim report following the analysis has revealed the results are inconclusive in defining the contaminant, the force said in a statement. The report does reveal, however, that the contaminant is similar in appearance to a number of commercially available pest poisons, it said.

The interim report does state if consumption of a similar amount of the contaminant - as found in the infected bar - were to occur, then ill-effects cannot be ruled out in people of small body mass, such as children who are potentially the most vulnerable.

The contaminated Snickers bar is currently undergoing further analysis in NSW in an effort to positively identify the contaminant, the police said.