Is Blatter in danger?
Whenever the dirt starts flying, he is fond of painting himself as Saint Sepp, the whiter than white leader who must suffer the organisation's little devils.
But now he stands accused himself as next week's presidential election race descends into complete chaos and acrimony.
The charge - levelled against him by his rival for the post Mohamed Bin Hammam - is that he was aware of the payments being made to Caribbean football officials which have landed the Qatari in the dock for bribery.
Sources close to Bin Hammam have told me that the report submitted by Chuck Blazer contains two witness statements which state Blatter was aware of the payments. One is Fifa vice-president Jack Warner, who is also accused of orchestrating the bribes at the Caribbean Football Union meeting on 10 and 11 May.
The other is unknown. But Bin Hammam's argument is that if what he himself was doing was wrong, then Blatter is also guilty of breaking the rules because he should have reported it.
Leaving aside the fact that this appears to be an admission of guilt from Bin Hammam for one moment, this is clearly a serious charge.
And under article 16 of its ethics code - which states that the ethics committee must 'accept' any complaint from a member of the Fifa executive committee - Fifa had no choice but to open another inquiry into Blatter.
But on the surface it is extrenmely difficult to treat the two charges with the same seriousness. One involves handing out bundles of cash to buy votes for next week's election, the other is not acting to bring that act of malfeasance to the attention of the Fifa executive committee.
There is also an important point here about evidence. Chuck Blazer's report has been compiled by US lawyer John Collins and includes sworn affadavits. Bin Hammam seems to be basing his case against Blatter on his interpretation of one element of the evidence filed against him.
So while this is all extremely embarrassing for Blatter, it's possible that he could be cleared on Sunday by his own ethics committee while Bin Hammam is suspended.
He will then make the case to the Fifa congress that he has been exonerated and should now be given four more years to clean up the governing body.
But this raises two other crucial questions.
Has Fifa's ethics committee really got enough time to consider all these charges properly?
And given Fifa's tarnished reputation, can it really be expected to carry out the thorough investigation which is clearly needed. Is it not high time the Swiss authorities intervened?
On top of all thiis comes the FA's own report on the corruption claims made by former chairman Lord Triesman.
The results of lawyer James Dingemans' inquiry were sent to Fifa general secretary Jerome Valcke on Friday afternoon. He is believed to have found some evidence to back up Triesman's claims against four Fifa executives - including an e-mail from Jack Warner which I reported on Thursday.
The Dingemans report is a minor tremor compared to the earthquake caused by Blazer's far more serious bribery claims but Fifa is probably going to have open yet more lines of inquiry.
It's a mess and if Fifa is to retain one iota of credibility it should call a halt to next week's election now.