(2) If such construction of masjid in graveyard is prohibited whether if the recently buried janazas are exhumed and buried in a new place and also the earlier buried janazas bones are collected and buried in some other place and then in that place whether the construction of the masjid in permitted.
(3) If the masjid is constructed in such a place whether as per the Islamic laws the jamah people of that area, persons constructed the masjid and those who helped to construct the masjid will get punishment. Please issue fatwa on the raised questions.
بسم الله الرحمن الرحيم
(1) No, it is not lawful to erect mosque in the graveyard.
(2) It is also not lawful.
(3) In the endowed land of graveyards only Muslims should be buried. The endower has endowed the land only for this purpose. It is not lawful to use it for mosque construction. It is unlawful to support in unlawful job. Such people shall be sinful.
Had you submitted your question after making the survey of the graveyard land with local Ulama then it would have been far better.
Allah knows Best!
Darul Uloom Deoband