The nine  words Emma Walters - wife of controversial union boss John Setka - allegedly 'told a private detective... as court hears her request that led him to press the record button on his mobile phone'

The estranged wife of controversial union boss John Setka was caught on tape asking a private detective to find her a gun to murder him, a court has heard. 

'I need to kill the father of my children,' Emma Walters, 46, allegedly told investigator Adrian Peeters during a meeting with him at her Footscray West home, in inner city Melbourne. 

Walters has pleaded not guilty to making threats to kill and attempting to acquire a firearm without a permit.

She had previously been charged with incitement to traffic a drug of dependence and incitement to commit conspiracy to murder, as well as committing an indictable offence while on bail. 

Those charges were sensationally withdrawn in August by Victoria's Director of Public Prosecutions. 

Walters appeared in the Melbourne Magistrates' Court on Tuesday to defend the remaining charges. 

The court heard Walters had contacted Mr Peeters via associates under the guise of wanting him to 'debug' her home. 

He attended her home on March 21 where it is alleged the pair had a brief conversation about the debugging exercise before the conversation took a sinister turn. 

'The accused wanted Peeters to obtain a piece ... and Peeters understood a piece to be a firearm,' a prosecutor told the court. 

The request caused a concerned Mr Peeters to begin recording the conversation on his mobile phone, a court heard. 

'I'm going to have to lure him in here and I'm going to have to use it. I know how to use a gun alright,' Walters was heard allegedly telling the private detective in a 22-minute video played to the court. 

'I just need a gun and I'm going to deal with the consequences of having to go through the court process of self defence. I have that capacity. I have to kill my children's father to survive.

'There's a question of premeditation so this conversation is never happening. You have no knowledge of it and once it's in court you cannot say that you have any knowledge of it.'

The court heard Walters allegedly bragged about knowing how to manipulate Victoria's justice system to run a self defence case once she had dispatched her husband. 

'I'm a lawyer by trade. From a legal perspective what will be asked about me is the question of intent. So I have to put him in a situation where I've accessed (the gun) and used it for the purpose of self defence,' she allegedly told Mr Peeters. 

Walters alleged that Setka had previously raped her and that she would a use a similar accusation to justify shooting him dead, the court heard. 

'He will try and rape me again and I have to be ready for that,' Walters was heard allegedly saying.

She told the private detective she planned to conceal the gun in a drawer, which would allow her quick access upon Setka arriving at her home, the court heard.

'I have to do it in complete self defence and I'm talking about I need to kill my children's father because I've got no other solution to the situation that I'm in,' Walters allegedly said.  

The court heard Walters had no qualms about murdering him while her children were present in the home. 

'I know how to use it. I'm not dumb like that ... I think the best (place to commit the murder) is here. Then the children aren't exposed to it,' Walters allegedly said. 

'Then the children don't see me killing their father, because that's what I'm going to do.' 

Mr Peeters described Walters as relaxed as she allegedly outlined her vicious plot.

'She wasn't really that concerned. When I asked her if there was children in the house she said "I don't give a f**k" ... she didn't really care about anybody or anything else ... about the children,' he said.  

In Walters' March 29 record of interview, which was also played to the court, she calmly sipped on a coffee as the allegations were put to her. 

'I've got nothing to hide,' she began. 

Walters painted a terrifying portrait of Setka in court, describing him as a controlling and abusive thug who used his powerful connections to bully and intimidate her. 

'I have a problem with his connection to Footscray police station,' she told a detective. 

Walters told police Setka had been subject to four intervention orders, which he had breached more than 10 times. 

'He's 125kgs and six-foot four with power and resources behind him and he doesn't like that I'm not doing what he wants me to do,' she said. 

'It's bad because I'm not agreeing to submit to what he wants, which is for me to publicly say that he's never done anything that he's done ... what he wants is to control me and because I'm not doing that is the very reason why we're sitting here now.'

The hearing continues.