A Canberra construction union organiser John Lomax is considering taking legal action after being cleared of blackmail.
Prosecutors did not present any evidence against former Canberra Raiders rugby league player when he appeared in the ACT Magistrates Court.
About 100 CFMEU members, including ACT branch secretary Dean Hall, were on hand to support Mr Lomax, brandishing flags and wearing fluro shirts with some performing a haka outside the court.
He walked out from his brief appearance through a guard of honour, pumping his fist in the air.
After going "through a bit of hell" over the past 10 weeks, Mr Lomax was happy to see sanity prevail.
"I'm only here to fight for worker's rights ... I never did my job to go to jail," he told reporters.
The CFMEU's general national secretary Dave Noonan called on Attorney-General George Brandis to explain how the charge came to be laid and how much public money was spent pursuing Mr Lomax.
"This isn't a dismissal on a technicality. This is an absolute slam dunk," he said.
Mr Noonan said federal police should not be dragged into the federal government's war against trade unions and workers.
The union would fully support Mr Lomax taking any further legal action.
His lawyer John Agius said the system had delivered justice but sadly after 10 weeks of having his family's name in the media.
"It's a little puzzling ... given this was a staged arrest, why legal advice wasn't taken before," he said.
Mr Lomax was charged with one count of blackmail in July by a police taskforce connected to the royal commission into trade union corruption.
Court documents had alleged he made an "unwarranted demand with menace" to a Canberra subcontractor, wanting him to sign an enterprise bargaining agreement with the CFMEU in 2014.