Three Foxconn workers have committed suicide at a factory in China in the past three weeks, according to a labour rights group.
The three worked at a plant in the central city of Zhengzhou run by the Taiwanese electronics giant.
A 30-year-old married man killed himself on Tuesday following the similar deaths of a 23-year-old woman on April 27 and a 24-year-old man three days earlier, media reports said.
"The reasons for these [suicides] are unclear," the New York-based China Labour Watch rights group said.
Foxconn, which assembles products for Apple, Sony and Nokia, has come under the spotlight after suicides and labour unrest at its Chinese plants since 2010.
In 2010, at least 13 Foxconn employees in China died in apparent suicides, which activists blamed on tough working conditions, prompting calls for better treatment of staff.
A 2011 report into conditions at Foxconn found slave labour conditions present, with staff complaining of being worked to tears, exposure to harmful disease, pay rates below those necessary to survive and military-style management that routinely humiliated workers.
Nets have previously been installed to catch suicidal workers, and factory staff have reportedly been required to sign "no-suicide" pacts in the past that also gave licence to Foxconn to institutionalise them if it saw fit.
Although Foxconn denied many of the accusations, it raised wages by nearly 70 per cent at its China plants in 2010.
It has also taken steps such as improving working conditions and enforcing age restrictions to address concerns raised by an independent audit of conditions mandated by Apple.
Foxconn is the world's largest maker of computer components and employs up to 1.1 million workers in China.