SEOUL, South Korea (AP) — A senior South Korean diplomat in Beijing became fatally ill after eating a tuna sandwich last month — a death that has left the envoy's family and his government asking China for an explanation.

The family of Whang Joung-il, 52, is worried about a government cover-up at a time when China is in the throes of a crisis over tainted products.

Whang, who was the No. 2 diplomat at the South Korean Embassy in Beijing, suffered severe stomach pains and vomiting after eating the sandwich from a nearby eatery on the night of July 28. He checked himself into Beijing's Vista Clinic the next morning and died two hours later.

China's government immediately got involved. It carried out an autopsy the following day to determine the cause of death, but no results have been revealed.

The family said China's Health Ministry informed the South Korean Embassy in Beijing on Aug. 5 that it had reached a tentative conclusion that Whang died of "acute myocardial infarction," a kind of heart attack.

Earlier this month, the South Korean Foreign Ministry summoned a top Chinese diplomat in Seoul to ask for an explanation.

"We've asked China to give us an outcome that is fair, objective and acceptable," a South Korean Foreign Ministry official said on condition of anonymity, citing the issue's sensitivity. China is expected to announce the results of the autopsy later this month, he said.

The family is also pressing to see the autopsy findings after an unusually long delay, considering the case involved a high-level diplomat.

The family is "deeply concerned that his death will be erased," Whang's son, Tae-ho, said in a statement Wednesday.

China's Foreign Ministry declined to discuss Whang's case in detail.

"We are investigating it," said Kuang Min, an official with the spokesman's office.

South Korean media speculated that Beijing was trying to deflect blame for the death by suggesting Whang had chronic heart problems. But Whang's family says he was healthy and had no heart problems.

Beijing is already sensitive about criticism of Chinese products. For months, it has been trying to allay international concerns about the discovery of high levels of chemicals and toxins in Chinese goods ranging from seafood and toothpaste to toys.

Chinese products have been subject to bans and recalls in the U.S. and elsewhere.

Whang's family claims the clinic should be held responsible in the death at least for bungling its response when Whang suddenly had difficulty breathing and his body went stiff.

"If they had called in an ambulance earlier, he could have survived," said Whang's son, adding the clinic called an ambulance 10 minutes after Whang stopped breathing.

The clinic declined to discuss the case.

A woman who answered the phone at the clinic but would not give her name said the clinic transferred the whole case to the Health Ministry, including the body and medicines. The Health Ministry will release a related report when it finishes its investigation, she said.