Tarek Elgayar faced the ACT Magistrates Court last week charged with dishonestly causing a loss to a Commonwealth entity and using a false document.

His list of 99 unauthorised transactions spanned much of 2018 and took him from Rottnest Island in Western Australia to the Blue Mountains and Jindabyne, as well as Melbourne, Brisbane and Sydney.

The $44,127 of expenses were neither approved, nor related to work.

The 27-year veteran of the armed forces used the card when he was on leave, on public holidays and on the weekend, court documents showed.

He used it for fancy hotels that cost well over what defence would have approved and in once instance bought a plane ticket for his partner.

The major's extravagant spending was discovered during a routine check but when questioned the officer insisted the travel was approved and he could back up the expenses.

When asked to explain the multiple large cash withdrawals, Elgayar said he had been using his personal card to pay for defence travel expenses to earn points and then withdrawing cash to pay it off.

Elgayar, who retired from the defence force in 2019, had also doctored documents trying to prove his spending was legitimate.

After signing a "record of conversation" with his lieutenant colonel, Elgayar said he had been "under the influence of ... quite a considerable amount of alcohol".

"So what I may have read and acknowledged by formal digital signature, may have been clouded," he said.

He also said: "My judgement has and was been impaired by my mental health, which was PTSD, MAJ depressive disorder, and an alcohol disorder which was diagnosed in 2015.

"In 2016 and '17, and 2018, into 2019 and even to today, I still heavily medicate myself with alcohol and it has impaired and clouded my judgement and my ability to control my impulses."

The former major later paid back nearly $120,000 but denied it was an admission of guilt.

"I don't see any benefit for anyone, to be honest, in a criminal conviction. It ruins whatever opportunity I may or may not have for the future. And I'm sorry, I'm sorry, I, yes, sorry," he told authorities.

But after an investigation he was charged and later pleaded guilty to the fraud.

Defence travel has to be approved by the appropriate delegate, and staff must estimate the cost of meals within official travel budget rates.

Official defence travel must be booked and paid for through official channels and any combination of personal travel has to be approved and then organised separately.

It is also against the rules for defence staff to accrue private points while on official travel business.

Elgayar was listed for sentence on July 14.

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: