The creation of a special "strike force" of FBI agents to quickly probe leaks of sensitive government information was recommended late last week in a secret memo to the White House by a group of government officials seeking to stop such disclosures, sources said yesterday.

But the proposed FBI unit has run into strong opposition from some senior White House officials, the sources said.

"We don't need another plumbers unit," said one source who has read the secret memo, referring to the ill-fated effort by the Nixon White House in the early 1970s to stop leaks of classified information to the press.

However, the sources said, there is a consensus among senior officials that the Reagan administration needs to take stronger action to discipline those who make unauthorized disclosures of classified and sensitive information.

The secret memo also indicated that polygraph tests may be used more widely to investigate government employes suspected of making unauthorized disclosures. One source said there is "no objection" to this approach among top White House and intelligence officials, although in the past it has drawn resistance fom Secretary of State George P. Shultz.

The idea of a special FBI unit to try to find the sources of unauthorized disclosures was advanced in a classified memo delivered to national security affairs adviser John M. Poindexter, sources said. Several of its other recommendations for discouraging government employes from leaking information, and for punishing those who do, were reported in yesterday's Washington Post.

According to the sources, the memo was prepared by a group of mid-level officials in advance of a meeting of a Cabinet-level group that has been focusing on the subject of leaks.

Members of the senior group, which was set up several months ago, include CIA Director William J. Casey, Shultz, Defense Secretary Caspar W. Weinberger and Lt. Gen. William Odom, head of the National Security Agency, the sources said.

Its second meeting was scheduled for Friday, when the senior officials were to consider the memo prepared by the mid-level group. That meeting, postponed because Casey was unable to attend, is expected to be held this week, the sources said.

One source said the memo immediately raised objections in the White House, where some officials considered a special FBI unit to be inappropriate.

"There are better ways to control leaks than with strike forces or a super FBI group, poised and ready to move," the source said. This source added that the objections from White House officials were that such an approach would be too high-profile and risky. The White House officials do not disagree with the goal of seeking out and prosecuting government employes who disclose classified information, the source said.

The suggestion of a special FBI unit comes as the administration is intensifying efforts to control leaks, which sometimes have embarrassed top policy-makers.

Two mid-level officials at the State Department and the Pentagon recently were fired for allegedly leaking classified information. Sources have said the firings were the direct result of a meeting of top legal advisers to these and other departments. The legal advisers, according to the sources, told their respective Cabinet members that the best way to deal with such unauthorized disclosures is to find and discipline those responsible.

Sources who have seen the memo from the group of mid-level officials said it called for using all means possible to protect sensitive national security information.

One source said the memo specifically mentioned wider use of polygraph tests. Two other sources said the use of polygraphs was strongly implied but not stated.

Although the so-called lie detector tests are widely used in the intelligence community for screening and as an investigative tool, administration efforts to expand the use of polygraphs to more government employes have been controversial. Shultz threatened to resign last December if asked to submit to a polygraph examination after President Reagan signed an order requiring thousands of government workers and contractor personnel with access to highly classified information to take routine polygraph tests.

On Friday, a White House official said the administration was taking a "dual track" approach of seeking better discipline among government workers as well as trying to persuade news organizations not to publish classified information.

Casey, among others, recently has raised the prospect of prosecuting news organizations that reveal communications intelligence under a 1950 law never before applied to the press. Casey's position is controversial in the administration.

"There is not going to be a press witch hunt" said one senior administration official. The official added that the Justice Department is reluctant to take up such cases. Another source familiar with the situation said it would not be worthwhile for the administration to "pick fights" with news organizations over leaks.

Casey last week referred to the Justice Department for possible prosecution an NBC News report on the charges against accused spy Ronald W. Pelton. Casey said NBC's report that Pelton had disclosed a secret eavesdropping operation called "Ivy Bells," which involved U.S. submarines operating in Soviet harbors, "if true," violated a 1950 law "against disclosing any classified information concerning communications intelligence."

The Central Intelligence Agency has been "reviewing" an article in Wednesday's Washington Post about the Pelton case. The article said Pelton had compromised a costly, long-running and highly sophisticated electronic eavesdropping operation involving U.S. submarines and a high-technology device that U.S. officials think is now in Soviet hands. The Post withheld some technical details of the operation after appeals from Reagan, Casey and other officials.