Is there any suspicion with regard to the death of Vladimir Lenin the undisputed leader of the newly created Soviet Union

His death and the possible mysterious reasons to it are nothing new, many great leaders have suffered the same and have been victim of many conspiracies of one kind or other.
Lenin had remained ill for quite a bit of while and had undergone many sufferings of physical form in form of ailing physique, crippled state, paralysis from time to time, he did recover in between but there was no major history of mental illness or family traces which could lead to assume one particular reason being the cause of his death. However still lots of suspicions are being drawn on many fronts from many authors about the possible causes of the poisoning and the unnatural death that Lenin might have suffered.
Under no circumstances could the conspiracy be ruled out since he was a leader of stature, a total different view, a revolutionary head and he had undergone life threats on number of occasions. The closest and almost successful of these was few years back when he was shot, however he had more to live and he escaped that attack. This along with lots of other undercover conspiracies, the relationship souring with Joseph Stalin, other rivals in the field, all this and the potential reason of conspiracy murder cannot be ruled out by any means.
Over period of time people have investigated into this topic and tried bringing out the possible reasons that might have contributed to the death. Some have looked into scientific evidence, others medical evidence, others on political intrigues, others of self request for poisoning. Though no single reason can be stated with hundred percent convictions yet all have some weight age to them.
To some, he was being taken out of the scene by his critic and rival at that time, Joseph Stalin, who later on went on to become the man in charge of the entire Socialist state(Mail). This concept is strongly held by historians and experts of such cases like Lev