After summing up the two days of "contradictory" evidence, Berkshire coroner Peter Bedford said he could not prove beyond all reasonable doubt that the businessman either took his own life or was unlawfully killed.
The body of the former Kremlin insider was discovered slumped on the bathroom floor at his ex-wife's luxury property in Ascot, Berkshire, with a ligature wound to his neck on March 23 last year.
While a report from a Home Office pathologist indicated there was "no suggestion of a violent struggle involving a third party", separate evidence from an expert on hanging and asphyxiation cases suggested Mr Berezovsky could have been strangled.
Members of the Berezovsky family declined to comment on the verdict as they left the court.
An open verdict into the death of Russian oligarch Boris Berezovsky, 67, was recorded by coroner Peter Bedford today.
Russian oligarch Boris Berezovsky was "strangled" by an assailant who then made it look like he had hanged himself, a professor suggested at his inquest.
Professor Bernd Brinkmann, an expert on hanging and asphyxiation cases, told the hearing that he believed two people were involved in the death of the businessman, who was discovered slumped on the bathroom floor at his ex-wife's luxury property in Ascot, Berkshire, on March 23 last year.
Giving evidence this afternoon, Professor Brinkmann told the hearing: "In my view there is no way for death by hanging [...] There exists two major, major concerns against."
Prof Brinkmann said the marks on his neck were "far away from the typical inverse 'V' shape" usually seen.
He suggested the exiled Russian could have been attacked suddenly from behind and quickly strangled, which was why there were no signs of a struggle.
A pathologist who carried out the post-mortem examination on Boris Berezovsky has told an inquest there was no indication that the tycoon had been strangled by anyone else.
Dr Poole said Mr Berezovsky's injuries were consistent with self-applied hanging, adding that evidence "was no suggestion of a violent struggle involving a third party".
He said that, as the businessman was not incapacitated by drugs or alcohol, he would have struggled if suddenly set upon by an assailant, even if this was from behind, and there was no evidence of this.
He added that, if he had been murdered, his body would have become a "dead weight", and therefore it would not have been possible for someone acting alone to have set up the scene in which he was found.
A major forensic report into Russian tycoon Boris Borozevsky's death found no evidence of poisoning or radiation, an inquest has heard.
Peter Bedford referred to a 22-page report submitted by forensic scientist Raymond Fysh, which detailed tests for poisoning including radiation and found no evidence of any.
A statement read out earlier by forensic scientist Sarah Tarrant said toxicology tests found traces of various prescription medicines in Mr Berezovsky's system, although it was not possible to tell when they had been taken or in what quantity.
Ms Tarrant also said she "couldn't rule out the possibility that he had ingested morphine or possibly even heroin", though the latter could have come in the form of poppy seeds found in food and herbal teas.
The daughter of Russian oligarch Boris Berezovsky thought he had been poisoned in the days after he lost a multibillion-pound court battle with football club owner Roman Abramovich, his inquest has heard.
Elizaveta Berezovskaya said her father told her "something strange was happening to him" and said "some chemical reaction was inside him" but they later realised he was suffering from depression.
Statements made by Ms Berezovskaya were read out to the court by Berkshire Coroner Peter Bedford, in which she claimed there were a number of people who were a threat to the former Kremlin insider.
Asked what she meant by this as she gave evidence today, Ms Berezovskaya said: "Because he was a target, always. My father was a very serious political figure."
However, the inquest also heard a first statement she gave the day after her father was found dead. In it, Ms Berezovskaya said she thought her father had killed himself and have often spoken of doing so.
One of the daughters of Russian oligarch Boris Berezovsky is expected to give evidence at his inquest today.
Elizaveta Berezovskaya is due to appear as a witness on the second day of the hearing into the death of the tycoon, who was yesterday described as a "broken man" after losing a bitter multibillion-pound court battle with Chelsea Football Club owner Roman Abramovich.
His body was discovered slumped on the floor by his bodyguard at his ex-wife's luxury property in Ascot, Berkshire, on March 23 last year.
Police said three things remained unexplained in their investigations into Boris Berezovsky's death, including an "unidentified fingerprint" in the bathroom in which his body was found.
ITV News' Romilly Weeks reports from a two-day inquest in London:
Police investigating Berezovsky's death concluded - Mr Berezovsky took his own life
However police say 3 things about Berezovsky's death remain unexplained: 1 - unidentified fingerprint in bathroom...
2 - witness saw stranger close to house 2 days before. 3 - two radiation alarms went off when emergency services attended
Boris Berezovsky spoke of "enemies" who were "trying to destroy him" before his death, a psychiatrist has told an inquest in London.
Dr Saeed Islam said Mr Berezovsky "perceived relentless pressure on him in terms of litigation and fear of losing those cases".
He said he also spoke of "enemies in Russia who were trying to destroy him and make him homeless".
Dr Islam told the inquest that Mr Berezovsky described feeling very low and told him: "I can't see a way out."
But he said that although Mr Berezovsky had suicidal thoughts, the tycoon had said it was not an option due to his Russian Orthodox beliefs and his family.