An ex-chairman of the Joint Chiefs of Staff denied bribery suspicions related to the country's procurement of military helicopters during overnight questioning, prosecution sources said Wednesday.
  

Retired Adm. Choi Yoon-hee returned home early in the morning after undergoing 20 hours of interrogation at the Seoul Central District Prosecutors' Office in southern Seoul.
  

He is suspected of receiving kickbacks from a defense firm in exchange for helping it win a contract for building military helicopters.
  

The 62-year-old, during the questioning, denied allegations that he directed his subordinates to make a false report to pick the Anglo-Italian AW159 Wildcat as the country's new multi-mission maritime helicopter, the sources said.
  

Choi was the Navy chief of staff when the Wildcat, which does not meet the required operational capabilities for the Navy, was selected in 2012.
  

So far, seven current and former military officials have been indicted on charges of making bogus reports on the helicopter's capabilities.
  

During the prosecutors' investigation, one of the defendants stated that it was all done under the direction of Choi.

  
Choi also stated that he did not know until his son was summoned that the son had received 20 million won ($17,200) from an arms broker, identified only by his surname Ham, and had repaid 15 million won.
  

The son denied any involvement by his father in the transaction, saying it was done individually, according to the prosecutors.
  

The summons was part of the prosecution's investigation into widespread corruption in the defense industry.
  

A special investigation team -- comprised of government, military and prosecution officials -- was formed to crack down on corruption in the industry after a series of shady deals came to light over the past year. (Yonhap