Crocker National Bank, the nation's 12th-largest, has filed suit against one of its vice presidents to recover $8.8 million in what bank officials call "false loans."

David Estes, 35, vice president and manager of Crocker's Construction Finance Office in the booming city of San Jose, "has been relieved of his responsibilities," said spokeswoman Betty Lattie at the bank's headquarters here.

The bank fraud, said to have been perpetrated for four years, was discovered recently after the alleged embezzler became "careless," said a bank investigator, who asked for anonymity. Bank officers noticed a lack of supporting documents for a multi-million-dollar housing development. Their suspicisons when confirmed when an officer observed an alleged similarity between the developer's signature and Estes' handwriting, according to documents mailed anonymously to The San Francisco Chronicle and verified by bank spokeswoman Lattie.

Two weeks ago the FBI entered the case.

Estes has not been available for comment, and his telephone number has been disconnected.

His lawyer, Richard White of San Jose, issued a statement yesterday saying "Mr. Estes denies any wrongdoing in connection with the alleged discrepancies which are in fact the result of the absence of internal controls at Crocker Bank. For nearly two weeks, David Estes has stood ready to secure the bank from any losses that may occur. However, the bank's internal disorder -- in particular the lack of communication and confusion as to the chain of authority among higher bank officials -- has resulted in a break in settlement negotiations.

The loans at first were small: $50,000 for a small lot supposedly purchased by Estes' parents. But by February, the loans in the Estes' parents name had mushroomed to $4.8 million for a nonexistent 96-unit housing development, bank officials said.

A second large loan for $2.8 million was made by Estes to the limited partnership of La Barbera Pueblo. He authorized an additional loan of $1.87 million for unknown purposes, bank officials said. They claim in the lawsuit that he took all documents for the last loan when he left the bank.

The loans total approximately $9.5 million; Estes repaid $700,000, leaving a balance of $8.8 million, the suit says.

Money from the large loan was used to buy expensive properties in the name of Jack and Mabel Estes, David Estes' parents.

Jack Estes is a well-known former assessor in the neighboring county of San Mateo.

According to the bank, David Estes operated alone, relying on "employes' loyalty," the bank investigator said. The senior Estes were not involved, the source said.

From their retirement home in Lockeford, Calif., Mabel Estes said that she and her husband own only the home they live in. "We're not involved. We know nothing," she added.

Because bank workers knew the parents and trusted them, and because David Estes was the office manager, the loans were granted withouth question, a bank vice president explained.

But the scheme began falling apart when the senior Estes supposedly purchased a 1.7-acre skateboard park in Campbell, Calif., for a large housing development to be called Hancock Village. The development existed only on paper. A $4.8 million loan was authorized even though there were no supporting documents.

A bank auditor compared the signature of Melvyn L. Kaufman, a bona fide developer who is building a Hancock Village elsewhere in California, with the signature of Melvyn L. Kaufman on the Hancock Village development in Campbell which had just received a $4.8 million loan. "The note bears the signature purported to be that of Melvyn L. Kaufman. It does not, however, bear any resemblance to the signature on the financial statements of Melvyn L. Kaufman in our files," the bank officer wrote in an internal memo. "The signature on the note looked very much like his -- Estes.'"

Estes, who lives in the Almalden Valley of San Jose in an handsome, expensively furnished home across from a golf course, drives a Mercedes Benz and also owns a silver Porsche.

The bank did not say how much he received as vice president, a position he was promoted to last September.

In its statement, Crocker Bank officials said that they are "confident that over a period of time the bank will fully recover the amount at risk."