Last October a whistleblower emerged from inside the OPCW alleging "irregularities" in its investigation of a suspected chemical weapons attack in the Syrian city of Douma.

The whistleblower was said to have supporting evidence in the form of text messages, emails and "suppressed" draft reports but, eight weeks after he first presented his allegations at a closed meeting in Brussels, only one document – an email – has so far become available for public scrutiny.

Why the other documents were not leaked along with the email is something of a mystery because if they show what they allegedly show they would provide some hard evidence to back up the whistleblower's claims.

A further complication in this story is that the whistleblower, who uses the pseudonym "Alex", has issued no public statement himself – so what we currently know about his allegations comes indirectly via third parties.

According to those third-party accounts, his central claim is that senior OPCW figures – possibly under political pressure – cherry-picked evidence in order to reach a "pre-ordained" conclusion.

As an example of this manipulation, he claims that in the summer of 2018, when the OPCW was preparing to issue an interim report on Douma, investigators who had been working on the ground in Syria were repeatedly sidelined and had their views ignored. We are told that this resulted in huge arguments within the OPCW.

The document at the centre of these arguments is a draft of the interim report, running to 105 pages, which had been compiled by members of the Douma investigative team. Their draft, we are told, was not well received and OPCW bosses responded by producing their own heavily doctored version of it.

Disappointingly, though, no one in possession of a copy has seen fit to leak the controversial draft, so there is no way of checking what it said or comparing it with what was eventually published.

'A non chemical-related event'

Another reason why it would be useful to see the draft is that whistleblower Alex has reportedly made some startling claims about its content which may or may not be accurate.

For example, he is quoted as saying that the draft described what happened in Douma as a "non chemical-related event" – in other words, that there was no chemical attack.

But is that what the draft really said? A look at the only relevant document that's publicly available – the leaked email – raises some doubts.

The writer of the email is unnamed but he is said to have been a co-author of the draft, so we can assume he's familiar with its contents.

According to WikiLeaks, which posted the email online, he was writing to express "his gravest concern over intentional bias introduced to a redacted version" of the draft. (In fact he wasn't, because the email talks of "unintended bias", not intentional bias, but never mind.)

The email was sent to the OPCW director-general's office and it makes a series of complaints about the way the draft report had been "redacted" and "modified" (for details see previous blog post).

If the draft did talk of a "non chemical-related event", those words must have been deleted somewhere along the line because they never appeared in the official reports and the OPCW's eventual conclusion was that there were "reasonable grounds" for believing a chemical attack had occurred.

If the authors of the draft (including the sender of the email) were convinced there was no chemical attack, and OPCW managers insisted otherwise, this would surely have been a major point of contention to raise in the email. Oddly, though, the email makes no mention of it.

Furthermore, the writer of the email does not appear to be denying that a chemical attack took place, but he warns against drawing conclusions that might undermine the OPCW's credibility. He comes across as cautious and somewhat pernickety. It is wrong, he says, for the management's revised version to talk about a "reactive chlorine-containing chemical" – the correct term is "a chemical containing reactive chlorine".

He objects to a statement in the management's revised draft that chlorine or another reactive chlorine-containing chemical was "likely" to have been released from two cylinders found at the scene. The email goes on to say: "The original report purposely emphasised the fact that, although the cylinders might have been the sources of the suspected chemical release, there was insufficient evidence to affirm this."

His point was clearly taken on board because the final report on Douma, issued in March this year, described the cylinders as a "possible" source of the chemical rather than a "likely" one.

'Not consistent with poisoning from chlorine'

There's a similar problem with another of Alex's claims: that the initial draft said the signs and symptoms of alleged victims were "not consistent with poisoning from chlorine".

The variety of symptoms observed in Douma has been a subject of much debate. Some of them were obviously not caused by chlorine but there were others, such as a burning sensation in the chest and sore eyes, that could have been.

Alex (as reported by Jonathan Steele) appears to be saying that after reviewing the symptoms the authors of the draft report ruled out chlorine.

However, this is not what the co-author of the draft says in his email. He expresses doubts about the evidence for chlorine among the symptoms but doesn't attempt to rule it out. He says the draft report contained detailed discussion of "the inconsistency between the victims' symptoms, as reported by witnesses and seen in video recordings". Because of that inconsistency, he says, "confidence in the identity of chlorine or any choking agent is drawn into question".

This falls well short of what Alex is reportedly claiming but is broadly in line with the OPCW's eventualy conclusion that "it is not currently possible to precisely link the cause of the signs and symptoms to a specific chemical".

Because he only communicates through third parties it's possible that Alex's claims have been mis-reported or misunderstood. If so, there's a simple way to clear things up: by producing the relevant documents – and in particular the contentious draft report. The longer we wait, though, the more it looks like the whistleblower has lost his whistle.