Week-long Italian court interrogations of two Turks jailed in the Netherlands and West Germany have helped corroborate some claims made by Mehmet Ali Agca about his plot to kill Pope John Paul II, but many other questions remain unanswered, according to legal sources here.

In effect, these sources said, the interrogations, conducted during the past seven days in their jails, have given credence to Agca's previous testimony that there were four Turks, not just himself, at St. Peter's Square on May 13, 1981, when Agca fired two bullets into the pope. The identities of all of Agca's accomplices, however, have not been clarified.

In his original trial in 1981 for attempting to assassinate the pope, Agca maintained that he had acted alone. He was subsequently convicted and given a life sentence. But in later interrogations that led to a trial of three Bulgarians and four other Turks, Agca admitted that a second Turk was with him at St. Peter's and, since the new trial began two months ago, has progressively implicated two others.

Because Agca's testimony in jail and in court has often been contradictory and because he has made claims that he is Jesus Christ, the court here repeatedly has sought independent corroboration of his testimony, upon which the trial of the three Bulgarians and four Turks seems to hinge.

That search last week took Judge Severino Santiapichi, public prosecutor Antonio Marini and one of the trial defense lawyers first to Maastricht, in the Netherlands, then to Bochum, West Germany.

Court officials have expressed "satisfaction" about what they have learned from Aslan Samet in the Netherlands and Yalcin Ozbey in West Germany.

Samet was arrested this year while carrying a Browning automatic pistol of the same type, and apparently coming from the same batch, as the pistol Agca fired at the pope. Ozbey, who is known to have been a close friend of Agca, was arrested last year on drug and false-documents charges.

Though neither man was implicated in Agca's testimony or named in the indictment of the Bulgarians and Turks, statements they had made in jail singled them out as potentially important witnesses. Legal sources close to the trial said that Samet was not very cooperative, often contradicted himself and raised suspicions that he might have had a greater involvement with Agca (whom he denied knowing) than previously thought.

Apparently the most interesting testimony, however, was Ozbey's during three days' interrogation.

Ozbey, legal sources said, convincingly testified that information he had received from some of the alleged participants in the plot against the pope was that Agca and three other Turks were in St. Peter's Square at the time of the shooting, though he differed with Agca in some respects as to their identities.

Agca has named his accomplices as his best friend, Oral Celik; a leftist from his home town in Turkey named Sedat Sirri Kadem and another Turk, Omer Ay, belonging, like Agca and Celik, to the extreme rightist Gray Wolves. Celik, whose whereabouts are unknown, is a defendant, in absentia, in the current trial; Ay is in jail in Turkey, and Kadem flew from Turkey voluntarily to deny Agca's charges in court here two weeks ago.

The trial itself has been adjourned for a month and is due to resume in mid-September.