Advanced Plumbing and Drains owner Jason Hooper said the ordeal he had been through had severely affected his life, lost him business, ruined his reputation, and put strain on his family.

He believes he was the subject of a union smear campaign, something denied by the former employee who accused him.

"There's never been any basis to the claims at all, which is one of the reasons we've fought so vigorously," Mr Hooper said. "I actually wanted my day in court."

"The impact on my life and my family's life since November has been very damaging."

"I've been with my wife, we've been married for 18 years, and seeing this sort of stuff in the press about her husband has not been nice at all."

Mr Hooper gave evidence to the trade union royal commission in July last year, saying the Communications, Electrical and Plumbing Union, and Construction, Forestry, Mining and Energy Union pressured the company to sign an enterprise bargaining agreement, and then intimidated him and disrupted work sites when he initially refused.

Months later, he found himself subject to a raft of accusations, including a worker's compensation claim, proceedings in the Magistrates Court, and a police investigation, which began after a referral from the royal commission.

The accusations against him were made by a former employee, Megan Williams, who alleged that Mr Hooper had instructed she falsify documents, which were later given to the royal commission.

Police have confirmed they are no longer investigating Mr Hooper and consider the matter finalised.

"ACT Policing has conducted an initial evaluation of the allegations against Mr Hooper and found them to be unsubstantiated," a spokesman said.

Mrs Williams has also discontinued a personal injury claim in the ACT Magistrates Court that had alleged that she had suffered injury and disability after Mr Hooper subjected her to bullying, threats, harassment, and unreasonable direction.

But she was paid out for a separate workers' compensation claim, and says withdrawing the claim in the Magistrates Court flowed from that.

Mrs Williams denies her allegations were part of a union smear campaign.

Her lawyer, Slater and Gordon's Martin Carrick, said it was Mrs Williams' decision to bring the case forward.

"This has been an extremely distressing time for our client and Mrs Williams is keen to move on with her life now the claim has been settled," he said.

"She is happy with the outcome and is looking forward to putting this experience behind her."