British Chem Attack May Have Occurred at Victim's Wife's Grave

Theresa May

The Metropolitan Police said the units were called in because they had "the necessary capability and expertise".

He reiterated Moscow's offer for assistance in the investigation, but said that "in order to have a serious conversation.you have to use the official channels".

For experts in chemical, biological and nuclear warfare, even seemingly simple tasks are complex and unsafe.

Police dismissed reports an exhumation and said there were no plans to carry one out.

Samples from the victims have already been tested by experts at the Defence Science and Technology Laboratory at Porton Down, a secretive military facility where nerve agents have been developed and tested over decades of controversial research.

British Defense Secretary Gavin Williamson said Britain was being "pushed around" by the Kremlin. "This is a terrible incident and my thoughts remain with the victims and their families".

Detective Sgt. Nick Bailey, a police officer who also fell ill, is in serious condition but is "conversing and engaging" with visitors, Rudd said earlier.

Investigators are looking into several theories of when and where Skripal and his daughter were targeted by the nerve agent, including if it could have been slipped in via a package or spray at his home or administered at a Salisbury restaurant and pub they visited before they were found unconscious.

He said: "There obviously are some indications the officer, and I'm very sorry that he has been injured, has actually been to the house, whereas there was a doctor who looked after the patients in the open who hasn't been affected at all". Unlike radioactive poisons, nerve agents dissipate quickly.

Moscow's military court convicted Skripal of "high treason in the form of espionage" in August 2006 for passing information to Britain's MI6 intelligence service.

A spokesman for British Prime Minister Theresa May said the poisoning was an "appalling and reckless crime".

The March 4 attack on Russian double agent Sergei Skripal and his daughter Yulia in Salisbury, southwest England, is being treated as attempted murder.

They are located at separate sites in the London Road Cemetery with each guarded by a police officer.

The cause of 59-year-old Ms Skripal's death was recorded as endometrial cancer and Alexander, 44, was said to have suffered liver failure while on holiday. At the cemetery, forensic tents were placed over the graves of Mr Skripal's wife and son.

Speaking to reporters during a visit to Ethiopia, Lavrov said Russian officials have seen no concrete evidence or "facts" about what happened to Skripal and his daughter.

Sources close to the investigation believe the chemical agent used is probably something other than Sarin or VX, the BBC reported.

Sergei Skripal until 1999, was a Colonel in the GRU - the foreign intelligence body of the Ministry of defense of Russian Federation.

Responding to previous comments by the interior minister, Russia's embassy in London tweeted on Thursday: "Totally agree with Secretary @AmberRuddHR: first evidence then conclusions on Mr Skripal's case".