The state of the U.S. economy is worrisome and there is a high possibility of a double-dip recession, one of the property market's most well-known economists said Tuesday.

Robert Shiller, professor of economics at Yale University and co-developer of Standard and Poor's S&P/Case-Shiller home price indexes, told Reuters Insider he does not know where home prices may be headed, but believes the economy may be on a precarious path.

"For me a double-dip is another recession before we've healed from this recession ... The probability of that kind of double-dip is more than 50 percent," Shiller said. "I actually expect it."

Shiller said he is unclear where home prices are headed.

"I don't know," he said. "I am taking a "wait-and-see" attitude," he said.

U.S. single-family home prices rose more than expected in May, reflecting robust spring sales spurred by homebuyer tax credits, the Standard & Poor's/Case Shiller home price indexes showed Tuesday.