The Dutch government today challenged the Salvadoran Army's account of how members of a Dutch television crew were shot to death in El Salvador last month. Without citing specific evidence, the Dutch government said it remains suspicious that the four journalists were slain in a planned ambush.

In a provisional report to a parliamentary commission in The Hague, the Dutch foreign minister, Max van der Stoel, said the Army's report that the crew died in a skirmish between guerrillas and government troops was "in parts questionable and not worthy of credit." The report added that "a deliberate attack on the journalists must not be excluded."

The official investigation, which included contacts with officials of the Salvadoran and U.S. governments and guerrilla leaders, will continue, van der Stoel said.

Privately, Dutch officials expressed disappointment that the U.S. government provided them with little assistance in the investigation. The U.S. Embassy in San Salvador said it did its own investigation and found nothing "to contradict" the Salvadoran government's version of the killings.

In a telephone interview, one Foreign Ministry source in The Hague said the U.S. investigation was "not thorough," adding that U.S. officials "did not provide us with the tools to work with." The source said that the U.S. Embassy in San Salvador had turned down Dutch requests for assistance in obtaining interviews with U.S. military advisers stationed at a barracks near the scene of the killings and with members of the Salvadoran patrol involved in the incident.

A State Deparment spokesman in Washington declined to comment on the Dutch complaints.

As some Dutch officials see it, the "very limited U.S. cooperation" and the fierce controversy stirred in the Netherlands by the killings of the newsmen have cast a pall over this weekend's visit to Washington by Dutch Queen Beatrix intended to celebrate 200 years of U.S.-Dutch friendship.

Opposition to U.S. support for the Salvadoran government is widespread in the Netherlands, and in recent weeks there have been several anti-American demonstrations. Following the journalists' deaths, a crowd attacked the U.S. Consulate in Amsterdam, breaking most of its windows.

There are still five crosses in front of the U.S. building, one for each of the dead journalists and a large, fifth cross with the inscription "40,000 Salvadorans."

Today the Dutch government also said it would "protest strongly" to the Salvadoran government for refusing access to the sergeant and 24 soldiers involved in the killings.

Dutch diplomats already have complained privately to Salvadoran government officials that a number of possessions the newsmen carried at the time of their deaths have not been returned.

The formal Dutch investigation into the killings on the afternoon of March 17 began two days later when the Dutch ambassador to Mexico, Jan Kees Speyart van Woerden, flew to El Salvador, where he is also accredited.

Salvadoran officials told him the four men had gone to Chalatenango Province to meet with and film guerrillas. They met with guerrillas on a sand road and had started walking toward guerrilla-controlled territory when they were suprised by a Salvadoran Army patrol. A skirmish followed, and the newsmen and four guerrillas were killed.

Today the Dutch foreign minister's report described its doubts as follows: "Given the fact that on the one hand the journalists involved were 'clearly suspected' by the government and on the other hand there were several opportunities for their approach to be signaled by radio to the Army patrol so that it could prepare an ambush, a deliberate attack on the journalists must not be excluded."

But the report continues, "The fact that the Army did not hide the bodies, but took them at its own initiative to San Salvador, mitigates against this."

The words "clearly suspected," refer to the fact that five days before their deaths the journalists had been picked up by the Salvadoran Treasury Police after the name of Koos Koster, one of the four, had been found in the pocket of a dead guerrilla.

The group was interrogated for five hours by Col. Francisco Moran, the commander of the Treasury Police, and released. Persons with access to government and military information in El Salvador said they had reason to believe that the group was then put under police surveillance.

The report said autopsies performed by Dr. Jan Zeldenrust, a Dutch pathologist, showed that the four men were not killed by bullets fired at a very close range as first reports indicated. There were indications that the group was fired on from two sides at distances of between 260 and 330 feet, it added.

It appeared most likely that the army patrol opened fire first and not the guerrillas, as stated by the Salvadoran authorities, the report said.

Among other "notable contradictions" between the official version and the findings of the Dutch investigation, the report referred to Army statements that the fire fight lasted 40 minutes, starting at 6 p.m., while the report said that it lasted from 5:10 p.m. to 5:30 p.m. The Army stated that between 20 and 30 guerrillas were waiting for the journalists, but the report said there were only four. The report also referred to the fact that the Army said it found only three weapons--a FAL rifle, a revolver and an M16--and no empty cartridges fired by these arms, indicating that no major battle had taken place.