Where we're at, there's little option but to suspend him and investigate.
tbf it probably wouldn't have got this far, if similar action had happened under Corbyn's watch. I don't believe he's an anti-semite, but he's proven a pretty ineffectual manager of his party, really. Great on the campaigns, sure he's great as your local MP but forget his politics, there was probably a reason he was always dispensable for many of the previous Labour leaders beyond the divergance of political view, and that's just he's not the best administrator, controller... leader.
Better to have a transparent process, clear him or not, move on, then have constant whispering.