The sister of an alleged former business partner of Lee Myung-bak has been questioned by the prosecution over a long-dormant scandal which engulfed the 2007 presidential election.

Erica Kim, sister of Kim Kyung-joon, returned to Seoul over the weekend to help the prosecution wrap up an investigation into the scandal involving stock manipulation.

With her brother Kyung-joon now serving an eight-year sentence for stock manipulation and spreading groundless rumors, her decision to return home is drawing attention from political circles.

Prosecutors said Kim had returned voluntarily. Her testimonies to the prosecution weren’t disclosed but observers speculated that she handed over key information about the “BBK case” ― which started with her brother manipulating shares of Optional Ventures worth 31.9 billion won ― which Lee was allegedly involved in.

Kim, a former Los Angeles attorney who also has been implicated in the fraud, has claimed to have contracts that show Lee’s involvement in the scam.

The court concluded the documents had been fabricated and vindicated Lee.

Kim has stayed in the U.S. since then and the indictment has ceased thanks to her American citizenship.

Her visit coincided with the arrival of Han Sang-yool, a former National Tax Service chief, who left for the U.S. in 2009 in the wake of a bribery allegation involving Grand National Party lawmaker Lee Sang-deuk.

Han was accused of allegedly having offered pricey paintings to former NTS chief Jun Gun-pyo in exchange for promotion. Han is also expected to have key information about real estate in southern Seoul, allegedly owned by Lee has denied ownership. Han was also spotted meeting the president’s elder brother, which amplified suspicion that the bribery scandal reaches all the way to the top of the administration.

The investigators summoned Han, who claimed to have visited Korea for his sick wife, Monday for additional questioning.

Political observers are busy assessing the implications of the sudden resumption of the long-halted investigations.

Rep. Park Jie-won, floor leader of the main opposition Democratic Party, suggested that the administration is trying to conclude the cases hastily in order to prevent the two explosive scandals from being dug up by the next administration.

“I cannot help but suspect that the administration has offered a plea bargain and other benefits to the two in exchange for collaborating with the current government against the next one, which might take advantage of the scandal to pose a major blow to them in less than two years,” he said.

“The DP will monitor and suggest the direction of the investigation if the whole probe seems to be a mere stunt,” he said.

A GNP insider reportedly said, “this isn’t a political gambit. It is just a coincidence.”

By Bae Ji-sook (baejisook@heraldcorp.com)