Silver Spotted Wasp

Size about 18mm. Quite large wasp with extremely long legs. It was found climbing around on our blueberry plant. I assume it was looking for some spiders. It was crawling fast. The body looks like it has large blobs of silver dots on its abdomen and body. It reminds of a robber fly but has definitely a wasp head. The waist is not very slim though. Legs hairy. Taxonomically, I can not place this wasp at the moment. I assume it could be Pompilidae. I actually found a pretty good photo match from New South Wales. It was removed from Flickr and I am convinced that its identification was wrong.