Police and striking CFMEU workers clash.

Police and striking CFMEU workers clash. Photo: Justin McManus

The Victorian police force is being used as a ‘‘political weapon’’, the construction union says, after a court heard that advice from government agencies triggered the arrest of a senior union organiser.

Victoria Police has withdrawn trespass charges against Mick Powell, of the Construction, Forestry, Mining and Energy Union, who was arrested on a building site at the Ringwood Aquatic Centre last month.

Ringwood Magistrates Court heard on Wednesday that Mr Powell was charged while inspecting the site on May 22. But WorkSafe documents confirmed Mr Powell had been officially invited there to deal with health and safety issues.

Under cross-examination, Constable Christian Mellican said state and federal government agencies – the Victorian Construction Code Compliance Unit and Fair Work Building and Construction – had told police that the union officials were illegally on the site.

Mr Powell was arrested and taken into custody.

When asked which legislation Mr Powell was charged with breaching, Constable Mellican said it was federal legislation, the Fair Work Act.

He said police were told about the laws after speaking with "a number of sources’’, which he later revealed to be an inspector and a director from the two agencies.

Slater & Gordon, representing Mr Powell, said the case proved the police force was being used as a tool to enforce the Coalition governments’ anti-union industrial relations campaign.

‘‘It’s hard to avoid the conclusion that Victoria Police has responded to the political pressure from the state and federal governments to arrest and charge CFMEU officials with criminal offences,’’ lawyer Marcus Clayton said.

A spokesman from the Construction Code Compliance Unit said it acted independently of government and liaised with police regarding operational matters when necessary.

CFMEU secretary John Setka said union organisers had been at the Ringwood site lawfully and the police response was politically motivated.

‘‘It’s shocking that the Victorian government would send the Victorian police in to stop our organisers and safety officers doing their jobs,’’ he said.

‘‘All Victorians should be concerned that the safety of building workers and community members are being put at risk by the Victorian government’s ideological campaign against the CFMEU.’’

Slater & Gordon told the court it would seek payment of Mr Powell’s legal costs from Victoria Police, estimated to be more than $10,000.

A police spokeswoman was unable to comment on the case within 28 days of the charges being withdrawn.

Fair Work Building and Construction also declined to comment.