Bahn Joo-hyun, managing director of a New York-based real estate firm, has been caught in the allegations of shady dealings over an attempted sale of a building.

The building is built and owned by Keangnam Enterprises, once chaired by businessman Sung Wan-jong who hanged himself from a tree on a mountain in April, following the allegations of dirty dealings with the Korean Government.

However, before killing himself, Sung blew the whistle on payments he made to the inner circle of President Park Geun-hye. That scandal is still unfolding.

In a new twist on the Sung saga, Bahn is suspected of stringing along Keangnam and its creditors when he took charge of selling Keangnam Landmark 72, the tallest building in Viet Nam. He allegedly faked a letter from a potential buyer, the Qatar Investment Authority (QIA), Qatar's sovereign wealth fund.

Bahn gave Keangnam a letter in which the QIA said it was basically a done deal.

"We are awaiting our Chief Executive Officer's approval while the Board of Directors of the QIA has primarily agreed to allocate funds for this transaction," the letter read. "The QIA expects to execute and perform the proposed contracts by the end of the month barring any unforeseen events."

Keangnam Enterprises handed over the document to its creditors in March.

The QIA has denied the letter.

"It's completely fake," said an official of the QIA. "They even faked my signature, and we don't even know Keangnam, the seller."

The construction of Landmark 72 was completed in 2011. The 72-storey building is 330 metres (1,083 feet) tall and stands on 610,000 square metres (150.7 acres). Keangnam Enterprises invested 1.2 trillion Won ($1.1 billion) to construct the building.

In 2013, it decided to sell the building to tide over some financial difficulties.

Korea Joongang Daily/VNS