Recurring pro-Kremlin disinformation narratives attacking the independence and integrity of the OPCW; painting the White Helmets as terrorists; and absolving the Syrian regime of responsibility for chemical attacks.
The term “reasonable grounds to believe” denotes a standard of proof which has been routinely applied in several areas of international law since 2002 (see e.g. Rome Statute, Art. 58(1). The same standards is followed by the IIT (Ltamenah report pp. 14-5; notes 30-2), the OPCW Fact-Finding Mission (see e.g. the Douma report, p. 4) and a number of UN bodies. See e.g. here (pp. 37-40) and here (pp. 62-3) for the UN definition of the "reasonable grounds" standard and an overview of the requirements for achieving it.
The IIT report makes clear (p. 3) that the investigation team was unable to access the site of the incidents owing to the non-cooperation of the Syrian government, despite "various requests" by the OPCW Technical Secretariat and the obligation on Damascus to cooperate with the OPCW under the Chemical Weapons Convention (Art. VII, para 7).
The report makes zero "references to certain secret services data [sic]". The ITT gathered information and evidence from "individuals, local entities, States Parties, and other international, regional, and local actors"; "interviews with alleged victims"; and "experts in the various subjects relevant to the investigation" (p. 61).
The notion that the 2018 chemical attack in Douma was staged by the White Helmets is a recurring conspiracy narrative. See here for our debunking of this disinformation claim.