He said that it included investigating ways of delivering nerve agents by applying them to door handles.
On Wednesday, during the UN Security Council meeting, Russia's UN envoy Vasily Nebenzya noted that Skripal, who had been convicted of spying, served his sentence and was pardoned.
"We have information indicating Russian intelligence service interest in the Skripals, dating back at least as far as 2013, when email accounts belonging to Yulia Skripal were targeted by GRU (military intelligence) cyber specialists".
National Security Adviser Mark Sedwill accused the country of spying on Sergei Skripal and daughter Yulia for a minimum of five years, and offered some specifics in a letter sent to NATO Secretary-General Jens Stoltenberg on Friday, reports Reuters.
Moscow has suggested Britain carried out the attack to stoke anti-Russian hysteria, but Britain asked the Organisation for the Prohibition of Chemical Weapons (OPCW) to check samples from Salisbury.
"The key institute responsible for this work was a branch of the State Institute for Organic Chemistry and Technology at Shikhany near Volgograd".
Turning to how exactly nerve agents are used by Russia, Sedwill said: "During the 2000s, Russia commenced a programme to test means of delivering chemical warfare agents and to train personnel from special units in the use of these weapons".
"It is highly likely that Novichoks were developed to prevent detection by the West and to circumvent global weapons controls". "Within the last decade, Russian Federation has produced and stockpiled small quantities of novichok under the same program".
Double Russian agent Sergei Skripal has been found unconscious after being exposed to an unknown substance.
The note demanded the withdrawal of one Georgian diplomat now serving in Moscow at the Swiss Embassy Interests Section, as Georgia and Russia have no diplomatic ties since the Russia-Georgia 2008 war and Switzerland has acted as a mediator.
He said Russia regarded at least some of its defectors as "legitimate targets for assassination", with the suggestion Sergei Skripal - a former member of Russian military intelligence sent to prison in 2004 after working with the United Kingdom - was on the list.
"We didn't produce Novichok, we didn't store this Novichok, so-called under the Western classification, was never in our military forces".
"We get the impression that the British government is deliberately pursuing the policy of destroying all possible evidence, classifying all remaining materials and making an independent and transparent investigation impossible", Alexander Yakovenko told reporters in London.
It was "highly likely that the Russian intelligence services view at least some of its defectors as legitimate targets for assassination", Mr Sedwill said in the letter.
He also complained at the continued refusal of the British authorities to grant consular access to Ms Skripal following her discharge from hospital.
Putin's man in London also mentioned Syria, reiterating claims the latest chemical attack on civilians in Douma was staged by rebel groups to draw the West into the war.