"Deep inside we all know who killed him."
There are Islamic Hadiths which claim that Mohammed was poisoned by a Jewish woman (presumably not with polonium radioactive materials, though with those Jews you never know).
That allegation helped justify the Mohammed-ordered ethnic cleansing of Jews and Christians from the area, though really this just continued a pattern of assault, murder and robbery that began under Mohammed and continued gathering force, and whose modern counterparts can be seen today in Syria or Gaza.
The Palestinian Authority likes to claim that Arafat was poisoned by Israel using polonium. Israel has been known to carry out the occasional assassination, but if it wanted to take down Arafat, it wouldn't be stupid enough to use polonium. That's something the Russians do, because they want everyone to know who was responsible. It's not clear that Arafat was poisoned by polonium, but if he was, it was probably because elements in the PLO, which was worked on by the KGB, got a sample from their old bosses without telling them what it was for.
In his sermon, PA Minister of Religious Affairs Al-Habbash preached that Arafat was murdered in the same way as Muhammad, repeating three times that Muhammad died from poison given to him in Khaibar - a town known for being Jewish in Islamic tradition:
"Yasser Arafat died a Martyr (Shahid) - we don't have the slightest doubt that they (i.e., the Jews/Israelis) killed him. One way or another, they killed him. Even Allah's Messenger [Muhammad] - they (i.e., the Jews) killed him with poison. When he was dying, he said to his wife Aisha: 'I feel the same pain I felt from the poison that I ate at Khaibar (Jewish village).' Poison that he ate at Khaibar. He continued to feel the pain until he died. 'I feel the same pain I felt from the poison that I ate at Khaibar.'"
Nevertheless, PA Minister Al-Habbash concluded his sermon as follows: "They killed him. Even Allah's Messenger [Muhammad] - they (i.e., the Jews) killed him with poison... Be satisfied, oh mighty one, oh Martyr Arafat, that you were killed the same way Allah's Messenger was killed... We have no doubt, and I don't think there is a single one among us who has the slightest doubt that Arafat was killed. Deep inside we all know who killed him."
Yes we do. Human immunodeficiency virus infection. Better known as AIDS. Or, in the Muslim world, Dancing Boy disease.
But back to the KGB and Mohammed, twenty years before Kristalnacht, Fanya Kaplan (a Jewish woman) attempted to assassinate Lenin shooting him in the neck and chest. The wounds supposedly contributed to his death. The Bolsheviks used the assassination to carry out the Red Terror. After Arafat's death, there was a series of attacks and assassinations against Palestinian Authority officials; including Musa Arafat. Mohammed's death led to a power struggle that took a generation to resolve.