Ehud Olmert, the Israeli prime minister, is undergoing yet another police probe.

Although a court has placed a gagging order on the details of the probe, leaked reports say it is over illegal use of campaign funds donated by a US citizen.

The reason the current investigation has attracted so much attention is the speed with which it is being carried out. Reports suggest the allegations are serious.

So what does that all mean for Olmert and his coalition? Will he survive this time? Or will he have to step down? And what is the likely impact on the latest reported breakthrough in peace talks with Palestinians?