George Hamar, a former investment officer at Virginia National Bank, sits in his spacious, but sparsely furnished home in the exclusive Baylake Pines section of this resort city and spends a lot of time on the telephone. He calls the news media, the White House, the Justice Department and an assortment of congressmen.

Nearly two years after he tipped off a bank regulatory agency about questionable practices in VNB's trust department - which he maintains eventually cost him his job - Hamar still doesn't think his story has gotten across.

After fruitlessly complaining to his superiors about what he considered to be improprieties in the management of the bank's trust accounts, or funds managed by the bank on behalf of clients for a fee, Hamar contacted the Office of the Comptroller of the Currency, which regulates national bank.

Among other things, Hamar told authorities that it was a practice for investment officers to buy stock, then wait a few days to see if it went up or down before deciding in which trust account to place the stock. His complaints sparked a confidential comptroller's office review of VNB's entire trust operation.

Hamar's allegations also led to an ongoing federal grand jury investigation fo VNB's trust department, an inquiry by the Securities and Exchange Commission, and a U.S. Labor Department investigation under the auspices of the Employe Retirement Income Security Act, aimed at determining whether trust department procedures resulted in losses to any pension funds or employe benefit plans.

But sources close to the grand jury suspect it has decided not to seek indictments, the status of the SEC probe is a well-kept secret, and a Labor Department official, who declined to be identified, said the department never to his knowledge has infringed on a bank's right to manage employe-related funds.

As for the comptroller's office review, it concluded, among other things, that there were "significant irregularities" in the management of the fund on which Hamar focused most of his complaints. The agency re-the value of the stock removed from the trust account, and the investigation led to a tightening of record-keeping practices in VNB's trust department.

Hamar, a short, 56-year-old man with brown hair and horn-rimmed glasses, is not satisfied, however. He often calls the news media and the others about his charges, and sometimes he reaches reporters at home. Not infrequently, he calls and immediately picks up a conversation of a week ago, not bothering to identifying himself.

He is convinced that there was wrongdoing at VNB, Virginia's largest bank, and he also asserts - as does a recent, comprehensive SEC report on bank securities activities - that there are inadequacies in the regulation of bank trust departments.

(In 1976, the latest year for which figures are available, 4,079 American banks had trust departments, supervising assets of $486.6 billion. Of these, 1,982 were national banks like VNB.)

The SEC report, which was prepared for the Senate Committee on Banking, Housing and Urban Affairs, says it is difficult to assess the effectiveness of examinations of bank securities activities, especially trust department trading activities, because the SEC doesn't participate in the exams or review them.

But it adds that the "primary focus" of bank examiners is on the bank's financial soundness and stability rather than on protection of investors, and it concludes that the two should receive equal consideration instead. The report also points to weaknesses in bookkeeping procedures in trust departments, which the nation's bank regulatory agencies have acknowledged.

Hamar's most serious allegation is that bank investment officers bought a large block of stock for Common Trust Fund A, an aggregate trust composed of more than 500 of the bank's smaller trusts, and then, after the stock rose in value, transferred 2,000 shares to 10 other accounts, including a VNB profit-sharing plan. Hamar said the transfer was backdated to the original cost of the stock, resulting in a $11,300 profit for those accounts.

Although the amount of money involved was relatively small, the grand jury has been trying to determine whether the transfer was intentional or an honest mistake, and whether it was an isolated case or part of a pattern.

VNB says the 2,000 shares never were intended for Common Tust Fund A and were put there mistakenly after the investment officer who ordered the purchase of the stock suddenly was hospitalized before he had a chance to fill out a slip stating which accounts the securities should be assigned to.

When he returned to the bank 28 days later, he and another investment officer discovered the mistake, reversed the entry, and placed the stock, together with its dividends, in the accounts for which they were intended, VNB says. The switch later was picked up in a routine quarterly audit, VNB says, and the trust fund was reimbursed the interest on the money used to buy the stock. Further renumeration was made after the comptroller's investigation.

In the end, "no account lost one penny," Wright Harrison, board chairman and chief executives officer of VNB, told shareholders at the bank's annual meeting last month. He said there were "certain breakdowns" in documentation procedures in block trading, but that new procedures have been implemented to prevent a similar situation from occuring again.