Samsung vice chairman a suspect in South Korean bribery probe

Lee has been summoned for questioning at 9:30 a.m. Thursday local time to address suspicions such as bribery, Reuters said on Wednesday. Specifically, prosecutors are looking into whether $25 million in Samsung payments to a business and foundations backed by Choi were connected with a 2015 decision by Korea's national pension fund supporting a merger of two Samsung units, Samsung C&T and Cheil Industries.

The investigation of Samsung's vice chairman centers on the merger of Samsung C&T and Cheil Industries.

A spokesman for the prosecutor's office refused to say whether any Samsung executives might be indicted, but didn't dismiss the possibility of issuing an arrest warrant for Lee. Two other senior Samsung Group officials have been summoned for questioning this week, but only as witnesses.

The head of the National Pension Service, Moon Hyung-pyo, was arrested last month after admitting he pushed the fund to approve the C&T/Cheil merger while he was health minister.

Lee, for his part, denied bribery allegations during a December parliamentary hearing, and prosecutors are looking into whether he gave false testimony.

The executive will likely face a skeptical reception, since Samsung is also said to have sponsored the equestrian career of Choi's daughter, Chung Yoo-ra. Chung was arrested in Denmark earlier this month, having been sought by South Korean law enforcement.

Samsung Group is the parent company of Apple's main competition in the smartphone space, Samsung Electronics, of which Lee is the vice chairman — his greater control is the result of his father being sidelined by a heart attack in 2014. Even if Lee is brought up on charges however, the Electronics division is expected to continue on unaffected, except perhaps for any long-term strategic decisions Lee might have made.

The Group is no stranger to scandal, since in 2008 Lee Kun-hee resigned as chairman after other executives were indicted for allegedly brokering a deal to give his children greater ownership in Samsung's holding company. He was even given a three-year suspended sentence for tax evasion, but was later pardoned.

Despite competing with the company, Apple has also been dependent on Samsung for key components. For years Samsung was the sole manufacturer of Apple's A-series chips, and Samsung Display is expected to be a major — perhaps exclusive — supplier of OLED panels for the "iPhone 8."