GUANGZHOU, China — An employee at a factory that makes iPhones in China killed himself after a prototype went missing.

Apple Inc. responded today by saying its suppliers are required to treat workers with dignity and respect.

The dead worker, Sun Danyong, 25, worked in product communications at Foxconn Technology Group, a Taiwanese firm that makes many Apple products at a massive factory in the southern city of Shenzhen, near Hong Kong.

Although Apple and Foxconn have confirmed Sun’s suicide, they have not provided details about the circumstances, which have been reported by the state-run Southern Metropolis Daily, one of the region’s most popular papers.

There’s tremendous pressure on employees dealing with Apple’s new products to maintain a high-level secrecy over the gadgets, traditionally launched amid great suspense and a big marketing buzz. Apple is also a constant target of prying journalists, rabidly faithful customers and competitors who make great efforts to try to steal a peek at its latest technology.

Sun was responsible for sending iPhone prototypes to Apple, and on July 13 he reported that he was missing one of the 16 fourth-generation units in his possession, the newspaper reported. His friends said company security guards searched his apartment, detained him and beat him, the paper reported.

In the early morning of July 16, Sun jumped from the 12th floor of his apartment building, the paper said.

Jill Tan, an Apple spokeswoman in Hong Kong, issued only a brief statement about the incident.

“We are saddened by the tragic loss of this young employee, and we are awaiting results of the investigations into his death,” Tan said. “We require our suppliers to treat all workers with dignity and respect.”

The hot-selling iPhone has helped make Apple immune to the global recession. On Tuesday, the Cupertino, California-based company said its earnings jumped 15 percent in the third quarter — growth propelled by laptop and iPhone sales.

More than 5.2 million iPhones were sold in the third quarter — seven times what it sold at the same time last year — and the spike in sales was partly because of a newly released version of the device, the company said.

One of Apple’s most important manufacturing partners has long been Foxconn, owned by Taiwan’s Hon Hai Precision Industry Co. — the world’s biggest contract manufacturer of electronics. The corporate behemoth also has produced computers for Hewlett-Packard Co., PlayStation game consoles for Sony Corp. and mobile phones for Nokia Corp.

Foxconn said in a statement its security chief has been suspended and turned over to the police.

The security official, Gu Qinming, was quoted by the Southern Metropolis Daily as saying he never hit Sun. Gu reportedly said after three security personnel searched Sun’s apartment and did not find the phone, the employee was ordered to go to Gu’s office on July 15.

The security chief said he didn’t think Sun was being truthful about the phone, the paper reported.

“I got a bit agitated. I pointed my finger at him and said that he was trying to shift the blame,” Gu was quoted as saying.

He added, “I was a little angry and I pulled his right shoulder once to get him to tell me what happened. It (the beating) couldn’t have happened,” the paper reported.

Local police declined to respond to questions from The Associated Press.

Foxconn executive Li Jinming said in a statement that Sun’s death showed the company needed to do a better job helping its employees with psychological pressures.

“Sun Danyong graduated from a good school. He joined the company in 2008. He had an extremely bright future. The group and I feel deep pain and regret when a young person dies like this.”