This is a false allegation on Al-Majlisi fabricated by our enemies who always try to put false allegations on us. Tahreef claims and narrations are in Sunni books from Ayesha who claimed that many verses were lost because it was eaten by an animal (Musnad Ahmad ibn Hanbal 6: 269 and Sunan Ibn Maajah 1: 625)

, and narrated from Umar ibn al-Khattab who claimed that Sura Al-Azhaab was as long as Sura Al-Baqarah.(Musnad Ahmad ibn Hanbal 5:132 and Al-Mustadrak Alal- Saheehayn  by Al-Haakim al-Nisabori 4:359).
Tahreef claim is refuted in our main books written by our leading Shia Ulama like Shaikh Al-Sadouq, Shaikh Al-Mufeed, Allama Al-Hilli, Shaikh Al-Tousi, Al-Shareef Al-Murtadha, Al-Shaikh Al-Tabarsi, Al-Shaikh Al-Bahaare, Al-Shaikh Kashif Al-Ghitaa', Al-Sayyed Sharaf Al Deen, Sayyed Al-Khoei and other great Shia Ulama. Al-Majlisi never said that Tahreef took place in Quran but he said that some people diverted the meanings of some verse from its real meanings. If fact Shaikh Majlisi stated clearly that Quran can never be distorted as Allah Has preserved Quran from adding on it or omitting from it or changing any word of it or any Tahreef. ( Bihar Al- Anwar, volume 9, page 113).

'Wassalam.