Many thanks to everyone for their helpful suggestions and pointers. I'm fairly sure now that the plant is cotoneaster franchetii; partly from perusing Janet's links and also from the detail on an Australian web page. Interesting - in England the plant is sold as an attractive garden shrub; in parts of Australia it is banned as an invasive pest. Perhaps the plant behaves better in a cooler climate? The Australian website said that each berry contains three seeds, so I picked a couple and opened them and there they were - 3 seeds per berry.
http://keyserver.lucidcentral....
If people agree on the identification I'll upload my photo to the plant database as suggested by Greene. Thanks again.
