The head of the Australian War Memorial, Brendan Nelson, was personally receiving payments from the multinational arms manufacturer Thales while publicly defending the institution’s controversial acceptance of donations from weapons companies.

The AWM has strongly denied any suggestion that Thales’s payments to Nelson for his work as a board member created a conflict of interest, saying Nelson donated any money he received and cleared the arrangement as required with the federal government.

The AWM has drawn criticism for accepting funding from weapons manufacturers, including Thales, which is a sponsor and supporting partner of the institution. The Medical Association for Prevention of War told a Senate inquiry last year such sponsorship was “contemptible” and pointed out the “stark” irony of an institution commemorating the horrors of war accepting money from companies that profit from conflict.

Nelson has been a staunch defender of the sponsorship arrangements, saying arms companies had a corporate responsibility to help explain “what is being done in the name of our country”.

Last month it was revealed through the federal government’s new foreign influence register that Nelson sat on the advisory board for Thales, a company in which the French government holds a 25% stake. Nelson’s role on the Thales Australia advisory board requires him to provide strategic advice to the chief executive and leadership team.

Guardian Australia has learned this position entitles Nelson to a fee from Thales.

Neither the AWM nor Thales would say how much that fee was.

The laws governing the AWM generally prohibit directors from taking payments for outside work, unless ministerial approval is first obtained. Failing to get such approval can trigger the termination of an AWM director’s employment, according to the Australian War Memorial Act.

An AWM spokesman said Nelson got no financial benefit from his role on the Thales advisory board, because he donated any fees he received to the AWM.

Nelson received all the necessary permissions before joining the Thales board, the spokesman said.

“Having been invited to join the advisory board of Thales Australia in 2015, Dr Nelson sought and received the consent to do so from the Chairman of the Memorial’s Council, Secretary of the Department of Veterans’ Affairs, the Minister for Veterans’ Affairs and the Australian Public Service Commissioner,” the spokesman said.

“Dr Nelson donates any and all fees for this role to the Australian War Memorial and as such received no financial benefit.”

But a former AWM director, Brendon Kelson, has criticised the arrangements. He believes there is a conflict of interest, regardless of whether the fee is donated.

“There’s a conflict of interest in my view. It’s a national cultural institution, he’s sitting on the board of a donor to the institution,” Kelson said. “All of that, it just looks messy.”

Thales has provided the AWM with general sponsorship support and backs individual exhibitions, such as the artist Ben Quilty’s After Afghanistan exhibit. It has also partnered with the AWM on the Napier Waller art prize.