Posted January 15, 2019 00:03:23

Photo: Senator Cash and former staffers have been subpoenaed to give evidence at a trial in February. (ABC News: Matt Roberts)

Commonwealth prosecutors will not pursue criminal charges against anyone implicated in leaks to the media about raids on the Australian Workers Union (AWU).

Lawyers for the Australian Federal Police (AFP) told the Federal Court on Monday there was little chance of a successful prosecution.

Media were tipped off that the AFP and officials from the union watchdog, the Registered Organisations Commission (ROC), were searching the Sydney and Melbourne offices of the union in October 2017.

Senator Michaelia Cash, then the Employment Minister, denied her office had any involvement in leaks to the media. But her senior media advisor, David De Garis quit over the saga shortly after, confessing to telling journalists the raids were imminent.

The ROC were investigating donations made by the union to activist group GetUp!.

The AWU has taken the ROC to the Federal Court, along with Mr De Garis and the AFP, arguing the investigation is seriously flawed and should be thrown out.

The AFP had launched an investigation into the leaks, and had been criticised for how long it was taking to reach any conclusions of wrongdoing.

In July, police handed over a brief of evidence to the Commonwealth Director of Public Prosecutions (CDPP) for consideration of further charges.

The Australian Workers Union offices have been raided in a donations investigation. Here's what they're being accused of.

Almost six months later, and after being ordered by Justice Jayne Jagot to update the court about any pending prosecutions by early January, lawyers for the AFP said charges would not be pursued.

"The AFP can confirm the CDPP has advised they will not be proceeding with a prosecution as there are no reasonable prospects of conviction," a spokesperson for the AFP told the ABC.

"The AFP considers this investigation finalised."

The Federal Court case continues as the AWU attempts to have the investigation dismissed in the wake of the leaks.

The union has subpoenaed Senator Cash and others to give evidence in the case.

All have strongly denied any wrongdoing, arguing they are not party to the proceedings, and accused the union of overreach.

The matter is listed for trial in February.

Topics: politics-and-government, government-and-politics, police, unions, law-crime-and-justice, canberra-2600, act, australia