The 48-year-old was arrested via a warrant from Victoria Police about 1pm yesterday at his electorate office at Tuggerah, on the NSW central coast.

The former Labor member was taken to Wyong police station, charged, and represented himself during a brief bail application in a magistrate's court that police did not oppose.

Outside Wyong Local Court, he made a brief statement and did not take questions even though it went "against the grain" as a politician.

"And particularly when every fibre of my being is screaming out to say how wrong this is," Thomson said.

"I'll be vigorously defending these charges. And as I have said from the start I have done no wrongdoing."

Court documents state the alleged offences occurred between February 2003 and April 2008.

The one offence listed in the charge sheet says he used a Mastercard to avoid paying a debt of $330 to Sydney escort service Aboutoun Catering for sexual services in February 2003.

He has previously denied allegations he misused union funds to pay for prostitutes, air travel, entertainment and cash withdrawals when he was national secretary of the Health Services Union (HSU).

Head of the NSW fraud squad, Detective Superintendent Colin Dyson and some of his officers were joined by Victorian officers in Thomson's arrest.

"I believe from reading the warrant that he was invited to travel to Victoria to surrender himself prior to Christmas," Det Supt Dyson said outside Wyong police station.

"He didn't do that, or refused, and the end result was the issue of that warrant."

Among Thomson's strict bail conditions, he is prohibited from contacting anyone from whom he allegedly secured sexual services. 

AAP