RUSSIA’S answer to 007 gadget whizz “Q” has vanished amid suspicions he masterminded the Salisbury poison plot, a Sun investigation can reveal.

Spy chief Oleg Martyanov ran an elite technology department developing military robots, bullet-proof uniforms and undetectable poisons.

He has now disappeared amid claims his experts produced the Novichok perfume bottle used to poison double agent Sergei Skripal, 67, and his 34-year-old daughter Yulia.

Martyanov, 58, fought in Afghanistan like ex-paratrooper Skripal, and was outraged at the betrayal by his former brother-in-arms decades later.

He had risen to become commander of Russia’s sinister Special Operations Forces when agents attempted to kill traitor Skripal.

But he quit suddenly in October, days after the two Salisbury assassins were unmasked as elite agents from Russia’s GRU foreign intelligence service — and has not been seen since.

His disappearance came as more evidence emerged suggesting the fiance of Yulia was a GRU “plant".

Stepan Vikeev, 30, has also vanished and it is claimed he made no attempt to contact Yulia as she fought for her life. He may have been recruited by GRU plotters in a “honey trap” in which Yulia led the assassins to her father.

Vikeev made just one call as Yulia fought for her life on the day she was attacked — to a suspected GRU intelligence service contact.

He is now believed to be “under the wing” of the spy service, which has links to his mother.

Mystery continues to shroud the outrage in which two GRU assassins tried to kill Skripal. But intelligence sources now believe ruthless Martyanov played a central role.

The decorated army veteran was promoted in 2013 to become the first commander of the Russian Defence Ministry’s new SOF — a reformed version of Russia’s SAS known as Spetsnaz. His prestigious post made him Russia’s version of Q, overseeing breakthroughs in cutting edge weaponry, including “extreme medical resources”.

Martyanov recently boasted of huge advances in the development of fighting robots and “invisible” bullet-proof uniforms.

A month before the Salisbury attack, he announced the launch of a project to build the world’s first drone submarine — sparking alarm among Western rivals.

But his stellar career suddenly crashed when he quietly quit “at his own request” on October 5 as details of the botched Salisbury plot were laid bare.

A source told The Sun: “Martyanov has disappeared off the face of the earth — it’s extraordinary.

“He was a war hero and a top military man in charge of an elite special operations unit, but overnight he has become a ghost.

“It’s not surprising there is speculation that his departure is linked to the Skripal attack. The timing alone speaks volumes.” Former GRU spy Skripal and Yulia nearly died when they were contaminated with Novichok sprayed on the door handle of their home in Salisbury, Wilts, on March 4.

Weeks later the assassins’ discarded perfume bottle was found and its deadly contents killed local woman Dawn Sturgess, 44, when she sprayed it on her wrists. Military sources in Russia said an old soldiers’ oath signed decades ago by both Skripal and Martyanov lay at the root of the events in Salisbury in March.

It warns: “If I violate this solemn oath... may the harsh retribution of the Soviet law and the universal hatred and scorn of the working people befall me.”

President and ex-KGB bigwig Vladimir Putin — who has also signed the oath — has publicly declared MI6 double agent Skripal to be a “traitor” and a “scumbag” and is believed to have privately sanctioned the mission to kill him.

And Martyanov shared his master’s contempt for the turncoat who, like him, had taken the oath prior to bloody missions during the Soviet campaign in Afghanistan years earlier. Martyanov stepped down and vanished days after SOF officers Colonel Anatoliy Chepiga and Dr Alexander Mishkin were identified as the Salisbury assassins.

They had been caught on CCTV walking near Skripal’s home after entering the UK on fake passports using the names Ruslan Boshirov and Alexander Petrov.

But Moscow sources told The Sun there was growing suspicion that the would-be killers were directed to the address using information gleaned from Yulia’s fiance Vikeev, who is four years her junior.

He swept her off her feet after meeting her at a birthday party.

But Stepan’s family were opposed to his potential marriage to the daughter of a convicted traitor.

His mother Tatiana Vikeev, 61, is reported to have links to the Russian secret service and refused to give her blessing to the engagement.

Yulia’s last phone call before flying to see her father in the UK in March was made to Stepan. And she was said to be heartbroken after recovering from her poison ordeal and hearing nothing from her lover and finding it impossible to contact him.

Yulia’s cousin Viktoria Skripal, 45, described Vikeev as “strange”, adding: “I am well and truly at a loss to understand Stepan’s behaviour.

“I am shocked and upset at the lack of contact from him.”

Mother Tatiana angrily refused to answer questions about his whereabouts. But a source revealed: “He has a new car and a new address and no one knows where he is.

“He has completely detached himself from his old life.”

A 60-year-old colonel who served in Afghanistan and knew both Skripal and Martyanov had no sympathy for Skripal and his ordeal. The veteran said at his home in Moscow: “Skripal is a bastard who betrayed his country for money. It’s not for me to say if he deserved to die or who was responsible.

“But he has got what he deserves now — a life of fear and suffering.”