A Chinese petroleum engineer who was mysteriously returned to China after seeking asylum in the United States has been reunited with his family and reassigned to his former post, the government said today.

A spokesman for the Foreign Ministry said Zhang Zhenggao, 47, came back to China "on his own request."

"The report that he was kidnaped back and punished by shooting is nothing but pure fabrication and vicious slander," said the spokesman.

The Washington Post reported yesterday that Zhang's friends said he apparently was kidnaped by Chinese Consulate officials in New York, placed on a Chinese airliner July 20, convicted of treason here and possibly executed.

The spokesman said Zhang "already arrived safely" and is back at work at the Petroleum Bureau of Sichuan province, in Chengdu.

When an American reporter asked if he could visit Zhang in Chengdu, he was told, "I'm afraid not."

Zhang went to the United States on April 5 as part of a Chinese delegation studying American oil-drilling techniques. A week later, he fled from the Chinese Consulate in New York by lowering himself down a fire hose and applied for political asylum.

According to the consulate, Zhang returned home voluntarily after getting a letter from his wife in Chengdu.

But his friends in New York said Zhang had gotten earlier letters from his wife and two children and never had expressed any interest in returning to China. Instead, he reportedly was trying to establish contact with Taiwan authorities after other Chinese defectors recently had been denied asylum in the United States.

Dr. Wang Bingzhang, a Chinese human rights activist in New York, said he had received reliable information from inside China that Zhang was convicted of treason shortly after returning to Peking. Wang said he also had an "unconfirmed" report that the engineer had been executed.

Zhang's case is believed to be the first of its kind involving the more than 1,000 Chinese visitors and scholars who have sought political refuge in the United States.