File photo of Liao Wan-cheng,?a former senior manager at Taiwan's technology giant Foxconn, has been detained in an ongoing probe into kickbacks from suppliers. [Photo / Taiwan.com]??

A former senior manager at Taiwan's technology giant Foxconn has been detained in an ongoing probe into kickbacks from suppliers, prosecutors said on Thursday after reports he pocketed NT$100 million ($3.33 million) in bribes.

Liao Wan-cheng was taken into custody late on Wednesday, while three other ex-employees were questioned and released on bail, an official at the Taipei District Prosecutor's Office said.

A second man, identified as Hao Hsu-kuang, was also detained on Wednesday and is accused of acting as a middleman between the former employees and suppliers, the official said.

The official told AFP that the five suspects could face breach of trust charges, an offence punishable by a minimum seven-year jail term if the amount in question exceeds NT$100 million. None of the suspects has currently been charged.

The detentions came after prosecutors questioned a dozen people on Tuesday and raided the ex-employees' residences and the offices of Foxconn's suppliers.

Taiwan media reported on Wednesday that Liao had allegedly pocketed around NT$100 million from suppliers by abusing his top position in a procurement committee that buys up to NT$50 billion of equipment a year, though prosecutors are still investigating the amount of the alleged kickbacks.

Foxconn has said that the alleged violations were limited to the procurement of consumables and accessory equipment, and that the company alerted the authorities in both Taiwan and the Chinese mainland following an internal audit.

The investigation is the latest setback for the company, which has come under the spotlight after suicides, labor unrest and the use of underage interns at its plants in recent years.

The allegations surfaced after Taiwan media reported last year that a manager at Foxconn - which assembles products for Apple, Sony and Nokia - had been detained by police in the southern mainland city of Shenzhen.

The manager from Taiwan allegedly solicited and accepted bribes from suppliers in exchange for buying their machines and equipment for the company, reports said, adding that this did not appear to be an isolated case.

Foxconn said at that time it was reviewing its acquisition procedures and the integrity of managers, and that its operations on the mainland had not been affected.

Foxconn, also known as Hon Hai, is the world's largest maker of computer components and employs about 1 million workers at its factories across China.