Jacqui Lambie's former senior adviser linked the senator's phone to his iCloud account without her knowledge so he knew who she was talking to at any moment, a court has heared.
The tenth day of proceedings for the unfair dismissal trial of Rob and Fern Messenger continued on Friday.
The pair were sacked by the senator in May 2017 after months of conflict between them.
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Senator Lambie's electorate officer Gemma Lynd told the court on Friday she felt the office was micromanaged by the Messengers after the 2016 election and found it difficult to communicate with them.
"It wasn't a very good place to work - it was toxic," she said.
"Everything you did was scrutinised.
"I believe a husband and wife working together was unprofessional and caused a conflict of interest.
"I felt they had a hidden agenda."
Former employee Aryelle Sargent told the court about the day Mrs Messenger visited the office while on sick leave on March 24 and placed documents in a bin to be destroyed.
This was after she was informed about Senator Lambie's intention to enter into formal mediation with her after instances of workplace conflict.
Ms Sargent said Mrs Messenger had put an unusually high amount of files in a bin to be shredded and had instantly shredded documents during the visit.
With other witnesses during the trial, Ms Sargent explained how Senator Lambie's phone and her calendar were linked to Mr Messenger's iCloud.
She said Mr Messenger had told her this was so he was aware of who she was meeting with and who she was talking to.
"He didn't want people calling Jacqui and swaying her on her position on policies," Ms Sargent said.
"When people called her, he could see it on his phone."
Another former employee Kirsty Balthazaar-Proctor said she had expressed feelings of mistreatment by the Messengers and concerns about her being tracked and monitored by Mr Messenger through the iCloud account.
"She had no idea they were doing that and about what was going on in the office," she said.
Hearings have been adjourned until next year with Senator Lambie expected to give evidence.