Playwrights Arthur Miller and Harold Pinter were censored from the pages of the Turkish press today after having given a press conference here in which they were strongly critical of the human rights record of this NATO ally.

The two vice presidents of the International PEN Club, a worldwide organization that promotes the human rights of artists and writers, came to Turkey last Sunday on a fact-finding mission. During their five-day stay, they spoke with more than 100 Turkish intellectuals, with former prison inmates, politicians and diplomats. As the playwrights put it, "the International PEN is concerned with the dignity of its members throughout the world."

At a press conference wrapping up their visit here Friday, Miller said, "It is almost impossible to discuss certain questions in the press here," as if to foreshadow the ban on their press conference that was handed down by the local martial law government several hours later. The two authors left Turkey before learning of the censorship.

Pinter, a Briton, said that they both were convinced that there is systematic torture in Turkey. He said, "From the information we have received since we have been in Turkey, which we regard as authentic, we believe that gross violations of the human spirit through physical torture is a present fact in Turkey. Our conclusion is that torture, despite the protestations and denials, is in fact widespread and systematic in military prisons and police stations in Turkey." He concluded by stating that he and Miller "naturally find this a deplorable state of affairs."

Miller said, "Only the pure at heart need no lawyers," quoting the judge in his play "The Crucible." He drew a parallel between 17th century witch hunts in Salem, Mass., and present-day Turkey.

Miller explained, "At a certain time in history the court permitted what was called 'spectral evidence,' which meant that it was not necessary . . . to prove that an accused person had committed an action. It was only necessary to prove that he had thought of it." Miller said that in Turkey "today people are brought into prisons on the basis of what they are alleged to be thinking."

Pinter, sitting on a platform where years ago his play "The Dumbwaiter" had been staged, praised the Turkish people for their dignity.

He said, "I would like to observe that both Mr. Miller and myself were deeply moved and impressed by the intelligence, the grace and the dignity of so many of the people we have met in Turkey, those who have suffered so much and continue to do so."

Although general elections were held in 1983 in Turkey and there is a democratically elected civilian government, many of the cases that were instigated by the military when it came to power on Sept. 12, 1980, continue to be prosecuted, and people remain in jail because of their beliefs and ideas.

After the military president, Gen. Kenan Evren, came to power following a period of political violence and general instability, tight restrictions were instituted over the press, universities and trade unions. Intellectuals, who periodically have been politically influential through Turkey's turbulent history, were tried for criticizing human rights abuses and calling for an amnesty for political prisoners. Such criticism is a crime under the current constitution of Turkey.

The martial law command was able to ban the comments made at the press conference from appearing in the Turkish press because there is still martial law in a number of Turkish cities, including Istanbul.

The liberal government of Prime Minister Turgut Ozal has been very careful in its relationship with the military, and he has been taking his time in lifting martial law entirely.

However, the government was embarrassed by the remarks of Miller and Pinter, especially since they were made a few days before the visit of Ozal to Washington to meet with President Reagan. The issue of human rights in Turkey has been on the agenda of the European Parliament and in European capitals since the 1980 coup.

The authors said they will prepare a report based on their talks here during the next few days and will submit it to the International PEN Club and Amnesty International. Pinter said the organization intends to present the report to the British Foreign Office and to the State Department.

U.S. Ambassador Robert Strausz-Hupe also was upset by the authors' comments. At an official reception in Ankara, Strausz-Hupe raised his voice at one point and told Pinter, "Sir, don't forget that you are a guest in my house." The argument started when Miller said, "There is either democracy or none of it."