Lech Walesa, the leader of Poland's banned Solidarity trade union, is likely to face much more difficult and dangerous trials once he is released than during the 11 months of his internment, one of his former advisers said today.

Confusion surrounded the whereabouts of Walesa today, following the announcement yesterday that the government intended to free him soon. The day was filled with rumors suggesting that the 39-year-old Solidarity leader may already have been freed.

A television program entitled "Government Monitor" reported that he had been "released from his place of internment," but the more authoritative late-night television news carried no such report.

Usually reliable Solidarity sources said they believed that Walesa was still at the government rest home at Arlamow in southeastern Poland, where he has been held since May. They said it was likely that the military authorities would want to reap as much propaganda benefit as possible from his actual release.

Earlier an official spokesman said that the internment order on Walesa was lifted today by the police commander in Gdansk at the request of the interior minister, Gen. Czeslaw Kiszczak. But the spokesman indicated that there could still be further delays in implementing the decision.

In Gdansk, Walesa's wife, Danuta, told reporters that she was expecting him home by Sunday. Hundreds of telegrams have poured into the Walesa home from well-wishers, and crowds of supporters were already reported to be gathering outside in anticipation of his homecoming.

The Communist authorities would obviously like Walesa to make his first public statement as a free man on state television -- a gesture that would be interpreted by many Poles as a sign that he was prepared to cooperate with the government. Since the military takeover last December, many union activists have boycotted the official mass media because of its anti-Solidarity bias.

Walesa's advisers are concerned that he should do nothing to jeopardize his enormous prestige among workers. At the same time, they are anxious that he avoid antagonizing the government or the Kremlin irredeemably by a rash public statement to the Western press.

"His position is going to be much more delicate than during the period of his detention. From the moment he steps out of the walls of that rest home in Arlamow, he will be walking along a razor's edge," the adviser, who asked to remain anonymous, said.

As leader of the striking shipyard workers in Gdansk in August 1980 and later of the first legally recognized independent trade union in the Communist world, Walesa became a symbol of the hopes of ordinary Poles for greater democracy.

Both sides are aware that his first acts and statements after his release from internment could have crucial psychological importance for future developments in Poland.

What government officials have described as "the Walesa myth" has grown as a result of his time in captivity. Merely by keeping silent and resisting government offers of emigration or an official position in return for his cooperation, Walesa has even greater popularity in the eyes of most of his fellow countrymen than he enjoyed before.

Once he is released, however, it will be very difficult for him to maintain this epic-scale reputation. Some Solidarity supporters will interpret the slightest concession to the government as a sellout, while others will find fault if he is unable to reach a compromise swiftly.

"I think that Walesa's release represents a great hope for national reconciliation in Poland, but whether this hope will be fulfilled or not depends both on how Walesa behaves and what the authorities allow him to do," his adviser said.

One of the government's motives in freeing Walesa could be to test the mood of society prior to the lifting of martial law, which is planned for the end of the year. The authorities hope that the excitement generated by Walesa's release will dwindle rapidly -- and that, treated as a private individual, he will pose no threat to their political control.

Walesa's former advisers, however, believe that he can continue to be a powerful symbol for the Polish people -- as long as he plays his cards carefully.

"Everything he does must be carefully thought out. If he makes a false move, he risks destroying himself and what's left of Solidarity, too," the adviser said.

As an example of a possible danger, the adviser cited "the first question Walesa receives in public about the Soviet Union. He will have to answer it in such a way as to satisfy the Kremlin and maintain his standing in a nation that blames Moscow for everything. That's a pretty formidable task."

Washington Post staff writer Richard M. Weintraub added:

Secretary of State George P. Shultz said that the impending release of Walesa "seems to be a good sign, from all we can judge about the situation in Poland."

Shultz, at a breakfast meeting in Washington yesterday with Washington Post editors and reporters, said Walesa's internment has been a "human tragedy. They wouldn't even let him see his baby."

Later, State Department spokesman John Hughes, in a statement reflecting a more cautious U.S. reaction, said Walesa's release would not be "a significant signal on its own. We would have to see what conditions he was released under."