British authorities have deployed members of the military to assist police in their investigation into the nerve agent attack on an ex-Russian spy as the former London police chief hinted the poison was in Sergei Skripals home. Londons Metropolitan Police said in statement that it had requested assistance from the military to remove a number of vehicles and objects from the site of the attack that left Skripal and his daughter in critical condition. The military was asked to help as they have "the necessary capability and expertise." Investigators are retracing the movements of the former spy and his daughter before they collapsed from nerve-agent poisoning, as they try to discover how the toxin was administered. Police have cordoned off sites including Skripals house, a car, the cemetery where his wife is buried, a restaurant and a pub. Skripal, 66, and his daughter Yulia, 33, were found unconscious on a bench in Salisbury on Sunday. Britains interior minister Amber Rudd, who visited Salisbury on Friday, said they were both still in a very serious condition. Former London police chief Ian Blair also said that a police officer who is in serious condition visited Skripals house — perhaps a hint that the nerve agent may have been delivered there. Blair told BBC radio that Det. Sgt. Nick Bailey "has actually been to the house, whereas there is a doctor who looked after the patients in the open who hasnt been affected at all. There may be some clues floating around in here." Russias Foreign Minister Sergei Lavrov said Moscow could help Britain investigate the poisoning but expressed resentment of suspicions cast on Russia. Lavrov has been quoted as saying by state news agency Tass that "whether its poisoning of some British subjects, whether its rumors about interference in the US election campaign, if assistance really is needed, then we are ready to consider its possibility." Lavrov added: "But in order to conduct such cases, it is necessary not to immediately run out on TV screens with unfounded allegations." The UK has vowed to take strong action against whoever was responsible for the "brazen and reckless" attack.