It is not a false that there are descendants of the Messengers of the Prophet (peace be upon him) present today. They belong to the Prophet (peace be upon him) through his daughter Fatimah (may Allah be pleased with her).
Al-Bukhari and Muslim narrated that the Prophet (peace be upon him) said, “Fatimah is a part from me). Accordingly, the offspring of Fatimah will be a part from the Prophet through Fatimah. Ibn Al-Qayyim said, “The scholars agreed to joining the offspring of Fatimah to the descendants of the Prophet (peace be upon him) who are entitled to invoking Allah’s mercy on them. This is because there was no daughter of the Prophet who left behind offspring except Fatimah.”
Ibn Al-Uthaimeen, a renowned Muslim scholar, said in his book Al-Sharh al-Mumti`, “If somebody said, ‘Are they existing? (i.e. Banu Hashim and Banu Al-Muttalib)’, we’d say ‘Yes, they exist. It is said that among those whose lineage to the Prophet people have validated, are the kings of Yemen whose reign ended with the recent revolution of republicans. They ruled Yemen for more than 1000 years ago and their lineages are well-known. They are renowned as being from Banu Hashim. There are many people as well pertaining to Banu Hashim.”
However, there are many people nowadays claiming that they are among the descendants of the Prophet but they are truly not from the prophet’s descendants (peace be upon him). They do so for bad intentions. It should be known that this is decisively prohibited and unacceptable as it incurs great punishment.
It is reported that the Prophet (peace be upon him) said: “Whoever knowingly claims to belong to anyone other than his father, Paradise will be unattainable for him.” (Narrated by Ahmad, al-Bukhaari and Muslim). Also, he (peace be upon him) said: “Whoever claims to be the son of anyone other than his father, or the slave of anyone other than his master, on him will be the curse of Allah, His angels and all people are sent upon him, and Allah will not accept from him any obligatory or mandatory action.” (Al-Tirmidhy)