A SECOND bottle of Novichok concealed in a perfume bottle is feared to lay undiscovered after being dumped by two Russian assassins.

Cops say they cannot be sure the counterfeit bottle of Nina Ricci perfume found by Charlie Rowley in Salisbury city centre was the same one used to target Russian double agent Sergei Skripal.

A large-scale search of the Wiltshire cathedral city by police looking for a second bottle containing the chemical warfare agent has now been concluded.

Counter-terror cops remain puzzled over where the two Russian military intelligence officers dumped the perfume bottle and applicator they used to pump Novichok onto Mr Skripal’s front door on March 4 this year.

And they stress they cannot be certain it was the same bottle inside a fake pink Nina Ricci box marked ‘Premier Jour’ which was found by 45-year-old Charlie almost four months later.

One source said : “There is still concern that a second perfume bottle containing Novichok may not have been discovered.

“A number of areas, including landfill sites, have been examined and those searches have now concluded without anything being found.”

Heroin addict Charlie says he discovered the perfume bottle in a bin behind a charity shop in Catherine Street on Wednesday June 27.

He collapsed after trying to fit the applicator to the bottle three days later and girlfriend Dawn Sturgess, 44, died after spraying the odourless oily substance onto her wrists.

But no traces of Novichok have been detected by scientists on two bins taken away by cops for analysis from the spot where Charlie says he found the perfume bottle.

Met Police Assistant Commissioner Neil Basu told a news conference on Wednesday : “We don’t yet know where the suspects disposed of the Novichok they used to attack the door, where Dawn and Charlie got the bottle that poisoned them, or if it is the same bottle used in both poisonings.”

Crucial time gaps also remain in the movements of the two Russian GRU military intelligence officers, who used the aliases Alexander Petrov and Ruslan Boshirov, during a recce they made of Salisbury and their trip back to carry out the attack the next day.

Mr Skripal, 66, and daughter Yulia, 33, were found unconscious on a bench in the Maltings shopping centre just after 4pm on Sunday while the Russian hit team were on a train back to London to catch an Aeroflot flight back to Moscow.

Mr Basu said : “We are particularly interested in establishing as much as possible about their movements during the period 2pm to 4.30pm on Saturday, 3 March, and 11.30am to 2pm on Sunday, 4 March.”

CCTV showed the smiling assassins walking along Fisherton Street at 1.05pm and a rear shot of them in the same road was taken three minutes later.

But cops have been unable to establish where they were in the 42 minutes before they flagged up again on camera at 1.50pm at Salisbury rail station - a five-minute walk from Fisherton Street.

It is a short distance from Queen Elizabeth Gardens, which was extensively searched by cops in Hazmat suits following the collapse of Dawn and Charlie.

Police have stressed they cannot guarantee there are “no other materials” in the Salisbury area and have urged the public not to pick up anything suspicious.

Public Health England say the risk is minimal - as they did before Dawn and Charlie fell ill.

The Russian suspects known as Petrov and Boshirov have been charged with conspiracy to murder Mr Skripal, the attempted murders of him, daughter Yulia and Wiltshire cop Det Sgt Nick Bailey, 38.

They are also charged of illegally possessing Novichok and causing GBH to Yulia and Det Sgt Bailey.

The pair, aged around 40, have not been charged in relation to Dawn’s death or the injuries to Charlie because it cannot be proved they dumped the Novichok perfume bottle in the bin where it is said to have been found.

British security chiefs believe they know the true identities of the Russian pair and are prepared to name them if their identities are confirmed.

*Anyone with information is urged to call the anti-terrorist hotline on 0800 789321.