I understand there is a movement in the UK and abroad that doesn't believe the mainstream story surrounding this.
And.. should we? Currently the police and security services are undergoing a major investigation into the murder of one person, and the attempted murder of 4 others. Plus unauthorised appliaction of a WMD, or just chemical weapon.
They have the apparent identity of the Salisbury tourists from their visas and passports. The media is merrily speculating on who might have done it, and potentially muddying the waters. Or just reducing the current suspect's likelihood of a fair trial.. In the unlikely event that they could be extradited to the UK to face trial. If the tourists are innocent though, I guess they've got a pretty good shot at defamation against media that's accused them.