Can someone tell me what's wrong with my figs? [link inside]

My father is growing figs and I thought today would be a good time to try some. The tree's outward appearance shows absolutely no signs that anything is wrong, and neither do the figs themselves until opening them up. The flesh seems to be fine, it's only when you get into the centre that the little stems are all dried up, almost rotten. This has also happened to my grandparents figs who live close by. We are in south-eastern Australia. Any help would be appreciated as we would really like to fix this!