SEOUL, South Korea — Boeing’s rivals in a South Korean tender for maritime patrol aircraft are crying foul over the U.S. aerospace giant’s hiring of a former high-ranking official at the agency in charge of the procurement.

The $1.8 billion competition, run by the Defence Acquisition Program Administration, is for the purchase of at least six new maritime patrol aircraft in addition to the existing fleet of 16 P-3Cs, DAPA spokesman Kang Hwan-seok said.

The complaints surround the hiring in 2016 of retired South Korean Air Force Lt. Gen. Park Shin-kyu as a consultant. Park had served as head of the DAPA’s weapons programs management bureau between 2014 and 2015.

Under the local rules of employment, a retired public official is not permitted to enter a company with duty relations for a certain period. This is meant to prevent influence peddling or illegal lobbying.

Park, however, signed a contract less than a year after retirement and didn’t undergo the government’s due scrutiny over duty relations, according to officials.

But Boeing argues Park, who has been with the company since 2016, didn’t require those steps and that there is no legal problem.

“Park is an advisory consultant who does not lobby, and only provides strategic advice. He is explicitly prohibited from promoting Boeing products or engaging in any sales advocacy with the Korean government,” said Paul Lewis, director of Asia Pacific communications.

“Boeing deeply respects Korean law and takes its compliance responsibilities very seriously. We have followed all relevant laws, and have demonstrated an unmatched level of openness and transparency.”

The DAPA has confirmed the exception.

“Overseas employment of a public servant is an exception of the duty relations rules,” a DAPA official said. “There is no legal problem, though some may raise ethical issues.”

“Park was in a top position at the DAPA, enough to wield an influence over key weapons procurement program,” a source from a European aircraft company told Defense News, speaking on condition of anonymity. “He could influence the MPA contest and other, such as an upcoming [airborne early warning and control system competition] competition.”

In response to the growing controversy over Boeing’s consultant contract, South Korea’s Ministry of National Defense is considering conducting an audit of the Boeing-Park contract.

“We’re collecting information on the MPA acquisition plan, as there are some reasonable suspicion over Boeing’s consultant contract,” a ministry official said. “If needed, we can launch an official audit of the contract problem.”

This story has been updated to include Boeing’s official statement.