David Parsons, the organisation's media director, said that it will maintain an involvement with the centre, including through provision of some running costs.
It is encouraging to see Germans taking responsibility for their own tragic national history
German Christians affiliated with the ICEJ were the primary givers. Some of the donors also flew to Haifa to volunteer for renovation work.
ICEJ International Director Juergen Buehler, who heads the embassy's branch in Germany, commented: "This gift will never make up for what they [survivors] suffered. But it does give hope for the present and for the future.
"It has been especially encouraging to witness so many Germans today who are willing to assume responsibility for their own tragic national history."
Open Eye, a newly-formed alliance of rabbis which seeks to draw attention to what is calls the "missionary enemy in Israel", has decried Christian involvement in catering for Holocaust survivors as "worrying".
The alliance, which attracted 500 people to its inaugural conference in Jerusalem last week, represents influential religious leaders including Beit El Chief Rabbi Shlomo Aviner, Beer Sheba Chief Rabbi Yehuda Deri, and Rehovot Chief Rabbi Simcha Hakohen Kook.
Its raison d'être is to demand that Israeli organisations stop accepting money from Christian bodies.
The alliance's coordinator, former Jerusalem municipal councilwoman Mina Fenton, said that while it is opposed to all Christian funds, it considers funds directed at Holocaust survivors to be particularly "problematic" as they are vulnerable and an "easy prey" for the missionaries whom she believes will use their connection with the home to access residents.
Ms Fenton was highly critical of the fact that Yona Metzger, Ashkenazi Chief Rabbi of Israel, attended the opening of the centre.
"If a rabbi goes there he gives a hechsher to the organisation," she said.
A source close to Rabbi Metzger denied this conclusion, saying that he attended only to "bless the survivors" and his presence should not be interpreted as endorsement for ICEJ.
Regarding concerns about missionarising, Mr Parsons said that his organisation is a "ministry of comfort but not a missionary organisation".
It donates to Israeli causes as a "humanitarian effort in the light of the history of Christian antisemitism" and has no desire to win converts as a result of the survivors' centre, he said.
But the rabbis in the alliance believe that whatever social action agendas Christian groups claim, the motivation is always missionary.
Rabbi Aviner said that while in past centuries Christians tried to convert Jews by force "now they want to buy us with money and by kissing, but we know what they want".
Rabbi Kook, citing similar logic, described the funding of the Holocaust survivor's facility as "terrible".
