A rapper’s widow is accused of murdering and dismembering him before drinking his blood.

Marina Kokhal has been released from custody and put under house arrest despite being the prime suspect in the killing of husband Andy Cartwright.

After the 37-year-old was held in August last year, her lawyers told how she was initially accused by detectives of “drinking her dead husband’s blood and having sex with his corpse” in St Petersburg.

Since then, although Ms Kokhal remains the main suspect, Russia’s best forensic scientists admit they have failed to prove that she fatally poisoned the rapper in collusion with her mum Elena Kokhal, 68.

Investigators claim the wife bought a hard-to-trace insulin substitute intended for diabetics and later administered an overdose to the Ukrainian rapper, whose real name is Alexander Yushko.

At the time of his death, the musician was having an affair with glamorous fan Nadia Romanenko, 25, it has since been established.

Criminal investigators claim they have evidence “that the murder was planned by the accused”, but admit to lacking proof she actually carried it out.

Ms Kokhal has admitted dismembering the corpse with a knife and hacksaw, but claims she did this so his fans would not know he had died from an “inglorious” drug overdose.

She strenuously denies murder.

Some of Mr Cartwright’s body parts were located in her fridge and others in bin liners intended to be chucked out.

His fingertips were fed to rats in the yard outside, it is alleged.

A video showed the smiling suspect as a St Petersburg judge freed her from custody, allowing her to be reunited with her and Cartwright’s son, now aged four, who she has not seen for more than a year while in detention.

Ms Kokhal burst into tears and hugged her lawyer Irina Skurtu on being freed from the dock, a glass cage, with Russian reports saying she was smiling as she left court.

Prosecutors had strongly opposed her release from custody.

Forensic experts say they were unable to check eight organs, namely, his stomach, pancreas, oesophagus, gall and urinary bladders, intestines, adrenal glands, and prostate gland.

They were either missing or had been put through a washing machine, the court was told.

All surfaces and utensils in the flat were ‘washed with vinegar”, say investigators.

Ms Kokhal had written a note saying she needed to buy an ultraviolet lamp, which experts say would highlight biological traces that had not been cleaned.

Detectives earlier suspected she injected a drug into his hand – where a needle prick was detected – and then killed him with a knife wound to the stomach.

But they are now working on the theory that she suffocated him.

She was granted house arrest but must not meet or speak to her mother who also remains under house arrest on suspicion of collusion.

Her child had been sent to be raised in an orphanage, but the judge has permitted a reunion.

Defence lawyers had earlier claimed that Ms Kokhal was quizzed on “disgusting” and “sick” claims.

They said she was asked: “Did you taste his blood?” and alleged that she had had “sex with the corpse”.

Her defence claimed this questioning amounted to illegal coercion to testify by use of threats.

They have argued that investigators taunted her by saying they would find a “good orphanage” for her infant son when she was jailed.