Mawlana Mahmood Ahmed Mirpuri (rahimuhullah) said:
“The hadith about (companions) drinking of the prophet’s blood is not authentic… Secondly even though (this narration) mentioned by scholars as imam Beyhaqi, this hadith was a weak chain. The hadith which states that Abdullah bin Zubayr drank the blood, has Hunaid ibn Al-Qasim in chain. His real name was Unaid, and was weak narrator in accordance to ibn Kathir, Bukhari, ibn Abi Khateem, Abu Dawud and Nasai. The experts consider this hadith weak and unacceptable. There is similar situation with the(similar) hadith about Malik ibn Sinaan”.
Abridged and quoted from “Fatawa siratal mustageem” p 74.