Virginia senatorial candidates Andrew P. Miller and John W. Warner continued to clash yesterday in Alexandria over how Warner became a top Navy Department official in the Nixon administration.

Miller, citing donations by Warner and members of his family to Richard Nixon's presidential campaigns called on Warner to make public details of his discussions with Nixon adminstration aides that preceded his appointment as Navy undersecretary in 1969 and as Navy secretary three years later.

Three hours later in the same room in a Holiday Inn on Eisenhower Avenue, Warner presented his former Pentagon boss, Melvin Laird, who told reporters he was indignant at Miller's charge.

"It's a false charge, and its a charge that will do harm to the Defense Department and the national security," the former Defense secretary said, his voice occasionally trembling with anger. "I hope Mr. Miller knows the kind of damage he is doing to the national defense."

Laird said later that the "damage" he feared was the suggestion that Defense Department jobs could be bought and solid in politics.

He said Miller's charge "reflects more on me as the leader of that department than it does on John Warner . . . I don't know Mr. Miller, but I do know John Warner. And I resent the charges that there were political contributions involved."

Laird said he alone made the appointments and said he had not even known of Warner's contributions until he read newspaper accounts about them yesterday. He said that he chose Warner as Navy undersecretary despite White House pressure for another candidate, whom Laird declined to name.

As that issue was being debated in Northern Virginia, another issue - Warner's wealth - reappeared in Richmond as Warner's campaign manager Judy Peachee disclosed that the GOP nominee has increased his personal loans to his campaign. Warner has now lent his campaign a total of $460,000, but has been repaid $139,000 she said.

Miller has also sought to make an issue on Warner's loans, citing statements Warner made early in the campaign that he would not make extensive use of his personal wealth as he had in his race for the GOP nomination. Miller, a former state attorney general, has accused Warner of trying to decide the election "on the depth of his pocket."

The announcement of the new loan total came as Warner released a final preelection contributions and spending report showing total expenditures and unpaid bills as of last Monday of about $814,000.

Warner reported total contributions from individuals and political action committees of about $456,000. The report showed outstanding loans by Warner of $321,000.

Democrat Miller, who has been consistently questioning Warner's credibility, once again seemed yesterday to have the Republican on the Defensive.

At a morning press conference in Alexandria, Miller quoted a Washington Post report that said that although Warner denied giving "one penny" to Nixon in 1972, public records show Warner gave $5,000 to the campaign. In addition to what the newspaper reported, Miller said that Warner's former in-laws, including philanthropist Paul Mellon and Richmond Mellon Scaife, gave over $1 million to the Nixon campaign.

Warners statements denying he gave money to Nixon came in a luncheon with reporters and editors of The Washington Post. At one point in the luncheon he had been asked if he had been "a big contributor to Nixon."

Later in the meeting Warner volunteered the statement that in 1972: "I didn't get involved in either Virginia politics or national politics. I did not contribute one penny to the '72 campaign for his (Nixon's) reelection. Not one single penny. From my pocket, or from my wife's at the time or from anybody else. I was totally out of it."

Warner's campaign office has subsequently released a list of checks totaling $4,900 that Warner made in 1972 to various Republicans. Of that amount $3,400 went to groups working for Nixon's reelection, the Warner campaign has said. Campaign finance reports obtained by The Washington Post, however, also list another $2,500 contribution from Warner to Nixon in 1972.That contribution was not listed by Warner's campaign office.

"My opponent has consistently woven a tangled web of conflicting statements," Miller said. ". . . This is the latest in a disturbing spiral of inaccuracies."

In response to Laird, Miller said later that he did not think his asking Warner to bare the record of how he was appointed was a threat to the security of the country.

"It's very important for my opponent to provide the people of Virginia in complete detail a statement as to the discussions that took place between himself and members of the Nixon administration as to the appointment of undersecretary and secretary of the Navy," Miller said at his press conference.

Laird, citing several Democrats he had appointed to defense jobs, insisted his choices were nonpartisan. He said he had known Warner since the Eisenhower administration both as a friend and as a lawyer, but that "I never dealt with him in a political way."

Laird characterized as "false" a report in yesterday's Washington Post that said four individuals involved in the 1968 Republican presidential campaign have said that the flow of the money from Warner and his wife at the time, heiress Catherine Mellon, had played a major role in Richard Nixon's decision to name Warner Navy undersecretary and then Navy secretary.

The Warner loans have been made to the campaign by a Richmond bank, but they are secured by the candidate's personal savings, making him ultimately liable for their repayment.

Earlier this year, Warner borrowed $491,000 to finance his bid for the Republican nomination and ended up paying the debt out of his own funds when he narrowly lost a convention contest to the late Richard D. Obenshain. Warner was nominated by the state party central committee on Aug. 12 after Obenshain's death in an Aug. 2 plane crash.

Peachee said of the latest Warner loan, "We intend that it will be paid back through other . . . contributions."