George V. Hansen, a seven-term Republican congressman from Idaho, was indicted by a federal grand jury yesterday on four counts of filing false financial disclosure statements, including three concealing his family's financial dealings with Texas billionaire Nelson Bunker Hunt.

After meeting for several hours with his lawyers, Hansen called the indictments a "political outrage," and suggested that they were in retaliation for his outspoken criticism of the Internal Revenue Service.

Hansen charged that the "selective and bogus prosecution is either a product of failed supervision of very young attorneys at Justice or the . . . politically motivated desire of the Department of Justice to silence my strong dissents and my opposition to federal intrusion into all our lives through uncontrolled taxation policies and enforcement procedures.

"It appears that those whom the executive branch cannot silence by argument, they tarnish by indictment very much to their own convenience. Retribution by intimidation has gone far indeed in this matter, and Mrs. Hansen and I will move aggressively to meet this political outrage," he said.

The indictments, returned in U.S. District Court here, were the first under the 1978 Ethics in Government Act for allegedly falsifying financial disclosure statements required under the law.

One Justice Department source said he expected the indictment to have a major impact in Washington, where virtually all major government figures are required to disclose annually their financial holdings, liabilities and transactions, including gifts, loans and profits for themselves and their spouses.

"By issuing this indictment based upon an untried and novel interpretation of untested federal laws, prosecutors . . . have this day outrageously and unlawfully impugned both my personal and political integrity and that of my wife, and have affronted my person and office as well as the constitutional privileges and immunities of Congress," Hansen said.

"I am convinced both as a matter of law and as a matter of fact that I am innocent of any wrongdoing . . . and that I will be vindicated."

If convicted, Hansen could face up to five years in prison and $10,000 in fines on each charge.

The grand jury charged that Hansen had neglected to report four major financial transactions:

* A total of $135,000 in personal loans to him in 1981 by three individuals in southern Virginia. They were identified as Odell Rogers, Carl McAfee and John Meade Jr.

* A $61,503.42 personal loan in 1980 to Hansen and his wife, Connie, made in his wife's name by Hunt.

* A profit of $87,475 made by the Hansens on the purchase and sale of 125 silver contracts worth nearly $4 million during a two-day period in 1979.

* A $50,000 personal loan made to the Hansens in Connie Hansen's name by the First National Bank in Dallas, and guaranteed by Hunt.

The indictments cover Hansen's financial disclosures for calendar years 1978, 1979, 1980 and 1981. His 1982 disclosure is not due until May 15.

The grand jury investigation into Hansen's financial dealings was triggered by a March, 1981, extortion letter to Hunt from Arthur G. Emens III, a former brokerage employe. Emens threatened to tell the FBI that Hunt allegedly made the down payment for the Hansens on 1979 silver contracts.

Emens, who was seeking a $440,000 loan from Hunt, later confessed to writing the letter, and received a suspended sentence. He assisted in the grand jury investigation. Emens told the FBI that the Hunts made the down payment to obtain Hansen's support for a bid on an Idaho silver mine.

At the time, both Hunt and Hansen denied any wrongdoing.

Hansen, 52, told The Washington Post in January that he felt he had been the victim of "headhunters" and "a very aggressive group of people in the press."

Hansen, who made no secret of his mounting financial problems, said that most of the loans were for his citizen taxpayers' group, which promoted his book attacking the Internal Revenue Service, entitled "How the IRS Seizes Your Dollars and How to Fight Back." Hansen once charged that the IRS was planning armed raids on homes in Idaho.

A conservative, Hansen has been a flamboyant figure in the House of Representatives. He served two terms from 1964 to 1968 and returned as part of the post-Watergate class of 1974 after defeating a Republican incumbent named Hansen and a Democrat named Hanson.

But within three months of taking office in 1975, Hansen pleaded guilty to two counts of violating campaign laws. He was fined $2,000 and sentenced to two months in jail. His lawyer was able to keep Hansen out of jail by persuading the judge that his client was "stupid, but not evil."

In 1979, Hansen outraged U.S. diplomatic officials and made headlines during the Iranian hostage crisis when he flew to Iran and attempted to negotiate the release of the American hostages.

Hansen also flew to Nicaragua in 1979, where he assured President Anastasio Somoza that the United States remained solidly behind him. He told the dictator that his problems with the United States were due to American journalists who had lied and "distorted" the Somoza story. Two weeks later, Somoza was overthrown.

The indictment does not affect Hansen's ability to vote in Congress. House rules prohibit voting by members convicted of a crime, but not those under indictment. Hansen sits on the Agriculture and Banking committees.