Will politics infect the Irancontra probe? Two special congressional panels and the new independent counsel have begun the second phase of the probe into the Iran-contra affair. But a squabble over the report of a Senate committee's preliminary investigation raises the specter of partisanship.

The full-scale congressional inquiry into the Iran-contra affair has not even begun. But a preliminary investigation, concluded last month, has already generated intense partisan wrangling on Capitol Hill. Signs of trouble came this week as Democrats and Republicans tussled over whether to release the findings of a three-week Senate Intelligence Committee inquiry into allegations that Reagan administration officials sold arms to Iran, then used the profits to fund antigovernment rebels in Nicaragua.

Over the objections of most of the panel's Republican members and the White House, the Intelligence Committee voted not to release the 160-page report. The committee's findings will be handed over to Senate and House select committees that are about to launch probes into the affair, however, together with an authorization to disclose portions of the report as the new investigators deem appropriate.

Some observers say this week's initial skirmish has raised doubts about the amount of bipartisan cooperation likely from the work of two special congressional committees scheduled to take up the investigation next week.

``This could be the beginning of a long, difficult season,'' one congressional source says.

In supporting the Democrat-led vote to keep the Intelligence Committee report under wraps, Sen. David Boren (D) of Oklahoma, the panel's new chairman, claimed that administration officials made ``massive revision'' of the document.

White House spokesman Larry Speakes yesterday described Senator Boren's charge as ``inaccurate.'' Mr. Speakes said that a team of administration officials who reviewed the document merely deleted classified information on ``sources and methods involving intelligence.''

The Reagan administration and Republican allies on Capitol Hill lobbied hard to have the final report of the Intelligence Committee made public. They said it would confirm that the Iran-contra operation was the overzealous work of White House subordinates who failed to keep President Reagan informed.

White House officials say evidence contained in the report that the President was not culpable - except, perhaps, in allowing his aides too much autonomy - will take the steam out of future investigations by Congress and a newly appointed independent counsel.

But Democrats say the document is too incomplete and inaccurate to be made part of the public record.

``Why all the hurry?'' asks Senate majority leader Robert Byrd (D) of West Virginia. ``It's all going to be revealed. But everything can be made known only after the select committees have done their work and after the independent counsel has completed his work.''

The decision not to make the report public has led to what amounts to a battle of leaks.

On Tuesday, White House officials disclosed some details of a chronology prepared by former National Security Council aide, Lt. Col. Oliver North, and submitted to the committee. The White House claims that Colonel North's chronology, which suggests that President Reagan gave prior approval for arms sales to Iran, conflicts with sworn testimony heard by the committee. The administration's intention apparently was to cast doubt on North's version of events.

The Intelligence Committee report was based on the testimony from current and former administration officials, including former national-security adviser Robert C. McFarlane, Attorney General Edwin Meese III, and White House chief of staff Donald Regan. Former national-security adviser John Poindexter and North refused to testify, invoking the Fifth Amendment. A copy of the report, together with recommendations on how to proceed, will be turned over to the two new congressional panels and to the independent counsel.

One private analyst says the real risk to the Reagan administration will not be efforts by Democrats to use the coming House and Senate investigations to embarrass President Reagan. The real risk, says John Palmer, a senior fellow at the Urban Institute in Washington, is that the actual details of the Iran-contra affair could put the President in a less than flattering light.

``The real uncertainty is not whether Democrats are going to play games with the investigation but how problematic the truth is going to be,'' Mr. Palmer says. ``If it turns out the President knew nothing of this, then the question is, why didn't he? If he did know something, then he's caught with his fingers in the cookie jar. Either way it's going to hurt the President.''