THE real estate bubble has burst for Veronica Hearst – widow of Randolph Hearst and stepmother of 1970s kidnap victim Patty Hearst – whose 52-room mansion in Florida has been a victim of foreclosure.

The Villa Venezia in Manalapan, just south of Palm Beach, is scheduled to be auctioned off on the courthouse steps on Feb. 25 to pay the $45 million Hearst owes to New Stream Secured Capital, which holds three mortgages on the property.

The Dutch-born socialite insists she has plenty of money, and claims her current problems were caused by “a conflict of interest” which she is about to resolve by refinancing.

But according to court papers, the widow has also mortgaged some of her art and pays $290,000 a year in interest on those loans.

“When Randy died in 2000, he made sure she was debt-free except for the house. He had to take out several bridge loans while he was alive to pay for her spending,” said a source close to the family.

“They almost feel bad for her – but she was just so nasty. The family hates her because she kept his kids from seeing him before he died,” said the source. “The day Randy died, the Hearst estate fired all of her Manalapan staffers and gave her 48 hours to get her stuff out of his Windmere estate.”

Last year, expenses on the 28,000-square-foot Manalapan mansion, designed in 1930 for the great-grandson of railroad baron Cornelius Vanderbilt, included $375,000 in property taxes, a $205,000 insurance premium and $44,000 in utility bills.

According to her 139-page deposition taken in October, Hearst also owes Corcoran real estate broker Geoffrey Thomas $17,000 he spent marketing the house before the sale offering was yanked.

While Hearst was trying to sell the property for $40 million, $10 million more than she paid for it in 2000, a neighbor offered her $20 million after hearing Corcoran was trying to unload it for even less.

“How do you know that?” asked New Stream lawyer Alan Grunspan. “The whole town knows,” Hearst replied. “The whole peninsula knows. People call me.”