Watchdog confirms UK findings on nerve agent used on Russian ex-spy

Moscow strongly denies involvement in the March 4 Salisbury attack, which has sparked an international row resulting in the expulsions of diplomats from all sides AFP/Adrian DENNIS

Separately, Russia shortly afterwards said it suspected British authorities of detaining the spy's daughter, who was poisoned with him, following her recent departure from hospital.

Samples tested by the Organisation for the Prohibition of Chemical Weapons (OPCW) "confirm the findings of the United Kingdom relating to the identity of the toxic chemical", the watchdog said.

It made no assessment of who was to blame for the Mar 4 attack, which also affected Sergei Skripal's daughter Yulia and a local policeman.

But British Foreign Secretary Boris Johnson said: "There can be no doubt what was used and there remains no alternative explanation about who was responsible.

"Only Russia has the means, motive and record."

Russia strongly denies involvement in the attack, which has sparked an international row resulting in the expulsions of diplomats from all sides.

Moscow on Thursday said it would not accept the conclusions of the international chemical arms watchdog, unless Russian experts are given access to the samples used.

"There is no information at all about how, from whom, in what conditions these samples were taken. This statement raises questions among Russian experts and, of course, requires additional detailed analysis," Russian foreign ministry spokeswoman Maria Zakharova said in Moscow.

Moscow fears the UK has forcibly detained Yulia Skripal, she added.

"We have every reason to believe this could be a question of the deliberate, forcible detention of a Russian citizen or possibly their coercion into a staged announcement," Zakharova said.

'KREMLIN MUST GIVE ANSWERS'

Experts from the OPCW took samples from the three victims during a visit to Britain last month, which were then tested in international laboratories.

In an executive summary made public at Britain's request, it said "the toxic chemical was of high purity" but did not name it.

That information and details about its structure would be in a classified report shared with OPCW signatories, it said.

Johnson said the chemical "was a military grade nerve agent - a Novichok", a group of deadly chemical compounds reportedly developed by the Soviet government in the 1970s and 1980s.

"We have called a session of the OPCW Executive Council next Wednesday to discuss next steps. The Kremlin must give answers," he added.

Prime Minister Theresa May's government has said Russia was known to have used Novichok, and pointed to the country's pattern of "reckless behaviour", including the annexation of Crimea.

Russia insists it has destroyed all of its chemical weapons and has responded angrily to suggests it targeted Skripal, a former intelligence officer who sold secrets to the British.

'I'M SAFE AND FEELING BETTER'

Skripal moved to Britain in a spy swap in 2010 and settled in Salisbury, and Yulia was visiting from Russia when they were poisoned, likely via contamination from his front door.

Despite initial fears that they would not survive, Yulia Skripal was released from hospital to an undisclosed location on Monday, while her father is said to be improving rapidly.

In a statement issued through British police on Wednesday, Yulia Skripal said she did not currently want any help from the embassy, adding: "I am safe and feeling better as time goes by."

She said her father "is still seriously ill" and said she herself is "still suffering with the effects of the nerve agent used against us".

She also distanced herself from her cousin Viktoria Skripal, who has spoken to Russian media about the poisoning and has sought to visit Britain, although her visa was rejected.

"I thank my cousin Viktoria for her concern for us, but ask that she does not visit me or try to contact me for the time being," Yulia Skripal said.