HEARTLESS thieves stole $4000 from a children's charity after "hatching a scheme" to dupe an elderly volunteer collecting money for the foundation in Sydney's CBD.

The theft occurred about 3.45pm on Sunday when the 70-year-old volunteer was working in Broadway shopping centre selling $2 raffle tickets. The money was being collected on behalf of the Kids with Cancer Foundation.

Police said a man and woman approached the volunteer and, while the male distracted him, the female snuck into his kiosk and stole the day's charity sales.

Police yesterday released CCTV footage of a couple wanted for questioning.

Superintendent Michael O'Toole said the crime was extremely disappointing: "It's obviously something these people have put some thought into and planned."

The plastic container which held the cash was later found discarded in a toilet garbage bin and is being forensically examined in the hope that fingerprints may be identified.

The CCTV footage clearly shows the two thieves casing the volunteer in the minutes leading up to the theft, Supt O'Toole said, adding: "It doesn't get much lower. You've got kids, charities and cancer, you've got a man who's working hard to try to make that better for them.

"This is money that now will not go to those kids with cancer - they will miss out."

Originally published as Heartless strategy to rip off charity