Sayyed Mohammad Al-Musawi,
Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to religious questions. In the past, he has also spent significant time in India guiding the community.
Yes, there are many authentic Hadeeths from the Prophet Muhammad (SAWA) and Ahlul Bayt (AS) stating that all of the infallible will be either killed or poisoned (ما منا إلا مقتول أو مسموم).
This Hadeeth was narrated by Imam Hasan (AS) from his grand father the Prophet (SAWA) after the martyrdom of Ameerul Mo'mineen ( AS). (Kifayatul Athar, by al-Khazzaz , page 160-162).
The Prophet (SAWA) himself was also poisoned. There are plenty of authentic narrations in Sunni and Shia books stating that the Prophet did not have natural death but was poisoned. ( Al- Mustadrak by Al-Haakim al-Nisaboori, V.3, P.60) and (al-Seerah al-Nabawiyyah by Ibn Katheer , V. 4, P. 449) and (al-Tabaqat al- Kubra by Ibn Sa'ad , V. 2, P. 249). These are few of Sunni books.