Assistant Secretary of State Chester A. Crocker met yesterday here with Lt. Gen. Johann Coetzee, chief of the South African security police, while the State Department was issuing a strong statement on a security police raid on the office and residence of a Washington Post correspondent in Johannesburg.

Crocker's meeting with Coetzee was part of a high-level U.S.-South African discussion centering on Namibia, the South African-ruled territory that the United States and other nations are seeking to guide to independence.

The State Department and the South African Embassy confirmed that a meeting took place, but spokesmen at both places declined to confirm or deny Coetzee's participation.

However, informed U.S. sources said the security chief was a member of the South African delegation.

U.S. policy generally is to restrict visits to this country by high-ranking South African military or police officials because of U.S. opposition to that country's racial policies of apartheid.

When the chief of South African military intelligence and four other high-ranking officers visited here in March, 1981, the State Department said U.S. consular officers did not know the visitors' identities when the visas were issued.

Since then, however, senior South African uniformed officers have come here on delegations to discuss Namibia in November, 1981, and March, 1982.

A State Department spokesman said the membership of the South African delegation to such talks is a matter for South Africa to decide. In this way it appears that meetings on Namibia are treated as a special case.

The raid Wednesday by South African security police on the home and office of Allister Sparks, South African correspondent for The Washington Post and the London Observer, was the subject of a statement yesterday by State Department spokesman John Hughes.

"The department strongly condemns any effort to restrict, fetter or otherwise intimidate press--actions which can only result in a diminution of information available to the public," Hughes said.

He noted that, according to the State Department's recent human rights report, "there has been a progressive deterioration of press freedom in South Africa over the last decade."

He added that nonetheless the press remains "a vital channel of communication" in South Africa and between that country and the rest of the world.

Hughes said the United States has raised the question of the security police raid with the South African government. Officials were unable to say whether Crocker had discussed it directly with Coetzee, the security police chief.

It was unclear whether any message was intended by South Africa in making the raid on The Post correspondent at a time when the chief of the security police was on his way to Washington.

Some U.S. officials said they found the timing "interesting" but there was no conclusive connection between the two events.

The principal roadblock to independence for Namibia, according to State Department officials, is the lack of progress on arranging the withdrawal of Cuban troops from Angola parallel with withdrawal of South African troops from Namibia.

Deputy Assistant Secretary of State Frank G. Wisner, Crocker's assistant, met earlier this week with Angolan officials in Paris, one in a series of recent high-level contacts between Washington and Luanda, the State Department confirmed. But there was no report on the progress, or lack of it, in Wisner's talks.