Former MP Craig Thomson would have needed photo ID to use a union credit card at a Sydney brothel, a court has heard.
Thomson, 49, is facing 145 dishonesty charges over the alleged misuse of $28,449 on Health Services Union (HSU) credit cards to pay for escorts, movies and personal travel while he was the organisation's national secretary and a Labor MP.
Thomson has pleaded not guilty to the charges.
Peter Lazaris, who owns Sydney brothel and escort service A Touch Of Class, said clients paying by credit card needed to show photo identification and prove authorisation to use the card.
He told Melbourne Magistrates Court transactions from A Touch Of Class appeared under the name "Staff Call" on clients' credit card statements.
A statement from Thomson's HSU-issued card shows $660 billed to Staff Call in 2006.
Thomson's half-brother Struan Robertson, who served as the HSU's national liaison officer, said that when issued with his own credit card, he was never given formal guidance on what it could be used to cover.
Mr Robertson said he instead used common sense and only used it for work-related expenses.
"My own sense of reasonable use guided me," he told the court.
HSU Victoria No. 4 Branch Secretary Rosemary Kelly told the hearing union credit cards should have only covered expenses that furthered the union's interest.
Ms Kelly said if a union leader was on a business trip, then incidental expenses could be covered by the cards, but should have been repaid.
"You wouldn't take the credit cards with you wherever you went and pay for personal expenses if you were in another city on business," she said.
HSU national president Lloyd Williams told the hearing an audit conducted when Thomson left the union had uncovered a credit card issued to Thomson which the union's finance committee did not previously know about.
He said he was "flabbergasted" to learn that Thomson had been withdrawing cash from the card.
The hearing continues before Magistrate Charlie Rozencwajg on Tuesday.
Thomson lost his NSW Central Coast seat of Dobell at last September's election, standing as an independent but receiving less than four per cent of the primary vote.