Found this online, for those of you who don't know, during the 1960s and 1970s, the Watchtower Society occasionally used the translation of the New Testament by Johannes Greber to support their similar renderings of John 1:1 and Matthew 27:52,53. In 1983 they officially stopped using his translation because of its "close rapport with spiritism." The information that Geber Was a Spiritist was readily available to the Society's writers. In 1955 and 1956 the Society's writers themselves wrote of Greber's spiritism. Their use of Greber's translation to support their New World Translation and their explanations for it is evidence of shallow scholarship.
Johannes Greber was a Catholic priest turned spiritist who translated the New Testament "with the help of God's spirits." His experiences with spirits and their communications with him are related in his book, Communication With the Spirit World published in 1932.
Greber's translation reads similarly to the New World Translation at Jn. 1:1 and Matt. 27:52,53. The Society quoted and referred to it in support of their controversial renderings of these verses in material they published from 1961 to 1976.
Here is a pdf of Communication with the spirit world - http://johannesgreber.org/downloads/Greber_Communication_-_web-final.pdf
RR