South Australia's Department of Planning, Transport and Infrastructure (DPTI) committed maladministration by funding thousands of dollars in hospitality for its former chief executive, South Australia's Ombudsman has found.

Key points: DPTI chief executive Michael Deegan was sacked by the new Liberal Government last March

DPTI chief executive Michael Deegan was sacked by the new Liberal Government last March The ombudsman found he committed misconduct by deciding on a Freedom of Information request into his own spending

The ombudsman found he committed misconduct by deciding on a Freedom of Information request into his own spending Mr Deegan says he "acted ethically and transparently" at all times

Its former chief executive Michael Deegan was also found to have committed misconduct by making the call on a Freedom of Information (FOI) request into his own spending, which he declined.

Ombudsman Wayne Lines also ruled that Mr Deegan's use of public funds to purchase meals, drinks and entertainment, and another senior executive's approval of his purchase card transactions were both "wrong" within the meaning of the Ombudsman Act.

Mr Deegan, a former chief executive of Infrastructure Australia, was appointed to the role by the former state Labor government in 2014.

He was sacked by the incoming Marshall Liberal Government last March alongside three other senior public servants appointed by the former government.

He is currently the chief executive of Sydney's Inner West Council.

In his report, the ombudsman criticised thousands of dollars of expenditure on Mr Deegan's purchase card between December 2014 and December 2017.

He highlighted:

A $214.50 meal at Press* Food & Wine with an external stakeholder, which included more than $100 in alcohol

A $214.50 meal at Press* Food & Wine with an external stakeholder, which included more than $100 in alcohol A $1,190.50 meal at Press* Food & Wine with five external stakeholders, including an "astonishing" $664 spent on alcohol

A $1,190.50 meal at Press* Food & Wine with five external stakeholders, including an "astonishing" $664 spent on alcohol A $262.50 meal at another restaurant between Mr Deegan, another senior DPTI official and a private stakeholder, including approximately $100 spent on alcohol

"A member of the public could rightly question the public value arising from the use of departmental funds in such circumstances," his report concludes.

"I am also doubtful of Mr Deegan's claim to have 'rarely consumed' alcohol during the relevant meetings.

"Save for in exceptional circumstances, I do not consider that it is appropriate for a public officer to consume alcohol in the performance of official functions."

DPTI operates Adelaide's train and tram networks. ( ABC: Ashley Walsh )

In an email to the ABC, Mr Deegan said he "acted ethically and transparently within the provisions of the departmental guidelines and the public service commission Code of Ethics at all times".

"In terms of the FOI process, the ombudsman said, at paragraph 128: 'There is nothing to suggest that Mr Deegan actively sought to insert himself into the process or direct any particular outcome. I note that Mr Deegan's execution of the document was consistent with DPTI's ordinary practice'.

"I categorically refute the rest of the ombudsman's report."

CEO met with minister over food and drinks

The ombudsman made special criticism of the department's practice of funding restaurant meals between the chief executive and other public officers.

"I note, in particular, that DPTI appears to have funded at least two CBD restaurant meals between Mr Deegan and the minister responsible for the department — at least one meeting of which involved the purchase of alcohol using department funds," Mr Lines wrote.

The report showed Mr Deegan spent $247.40 on "dinner with Minister Mulligan (sic)" at Press* Food & Wine in September 2017.

Treasurer Rob Lucas said former transport minister Stephen Mullighan needed to offer an explanation.

"Mr Mullighan now needs to explain why he needed to be meeting his own CEO at restaurants in the Adelaide CBD rather than saving taxpayers' money by meeting his own CEO in his office," Mr Lucas said.

While he did not remember specific details of the meals with Mr Deegan, Mr Mullighan did defend attending dinners funded by the Government.

"I don't recall the details of those specific dinners but it's my recollection that I only ever attended these dinners where the Government incurred the expenditures which were work related," he said.

Mr Deegan explained to the ombudsman that one of the expenses on his card, an $860.50 spend at The Barn steakhouse in Mount Gambier, was made "when the minister or ministers attending had left their own credit card in their rooms".

In 2017, Mr Deegan tried to bring in a zero-tolerance alcohol policy for DPTI staff, extending the policy for train drivers to all staff.

"We believe it is reasonable and right to have a zero-tolerance policy against illicit drugs and alcohol, with an accompanying education and awareness program to support its introduction," Mr Deegan said at the time.

The zero-tolerance policy was never implemented.

Probe started with an Opposition request

The genesis of the ombudsman's probe dates back to 2016, when then Shadow Treasurer Rob Lucas made an FOI request for copies of all invoices and expenditure by the DPTI chief executive, in particular relation to alcohol and meals.

Mr Lucas said his request was prompted by the fact that previous FOI requests had embarrassed a number of ministers.

SA ombudsman Wayne Lines published his report today. ( ABC News: Nicola Gage )

"We were advised that ministers were starting to avoid scrutiny by having CEOs or chiefs of staff using their credit cards to pick up the bills," Mr Lucas said.

The department twice refused to provide the information to Mr Lucas, prompting the ombudsman's external review.

The ombudsman found that the department breached the Freedom of Information Act by delaying supplying him the relevant material for about a year, an act he described as "wholly unconscionable."

The documents were finally compiled in January 2018.

"By refusing to provide these invoices when required by the ombudsman, Mr Deegan managed to prevent the release of any of these embarrassing invoices until after the 2018 state election," Mr Lucas said.

The Treasurer said the State Government would consider the ombudsman's recommendations, which include that it develop a whole-of-government policy relevant to the purchase of meals, drinks and alcohol using public funds.