Parliament security tasted white powder

A security officer who tasted an unexplained white powder on a balustrade in Parliament House says if it was anthrax then he had already been exposed to it.

Former AFP officer Graeme Anderson said he put his finger in the white powder - which turned out to be sugar - because there was no evidence it was suspicious.

"The only question in my mind was whether that substance was salt or sugar," Mr Anderson told a Senate hearing on Monday.