Rabbi Ovadia Yosef, who heads the ultra-orthodox party, told party Chairman Eli Yishai that he never made the statement about Kadima, founded by Prime Minister Ariel Sharon, reports Ha'aretz.
The rabbi was further quoted as saying: "Had I wanted to say such things, I wouldn't be ashamed of doing so."
Yosef had recently said that anyone voting for Shas in next week's general elections is ensured of a spot in heaven, the report said.
A Kadima spokesman said: "Whoever votes for Kadima is voting for hope and for Sharon's policy, and is ensuring that Israel will be a better place. That is the real paradise."
Separately, Ynetnews.com reported that Yosef has said he didn't establish Shas for gaining political power but to spread the Torah among Israelis.