A high-ranking Chinese official was dismissed last year after letting a top-secret document analyzing Sino-U.S. relations fall into the hands of U.S. diplomats, according to a Hong Kong newspaper report reaching here yesterday.

The newspaper Ming Bao said that a department chief of China's Foreign Trade Ministry left behind his briefcase containing a copy of the sensitive document during an official visit to the U.S. Embassy, Washington Post correspondent Michael Weisskopf reported.

U.S. officials confirmed today that a member of a Chinese foreign trade group that visited the embassy in late 1979 or early 1980 forgot his briefcase. However, the American diplomats said, the item was promptly returned to the official when he came back looking for it.

Acting U.S. Ambassador to China J. Stapleton Roy declined comment when asked if any document had been removed from the Chinese official's briefcase and photocopied before he reclaimed the bag. According to Roy, "The embassy adopts a standard policy of refusing to comment on stories of that kind."

China's Foreign Ministry also had no comment.

Ming Bao, which is believed to have excellent contacts with the Chinese leadership, said the document in question had been drafted in February 1980 by Chinese Embassy officials in Washington.