Acting Justice Brian Martin AO wore a black material mask during the trial, having recently arrived in the state from South Australia.

When summing up in the trial of Dane Andrew Clark who was found not guilty on Thursday he switched to a medical mask.

"I am told the change in mask helps my voice carry," Acting Justice Martin told the jury.

"I am wearing it because I was in South Australia after July 8 arriving in Tasmania on July 17.

"The directions are to wear a mask in a public place and strictly speaking I am not required to wear it in here, but out of an abundance of caution I am doing so."

Acting Justice Martin had conducted remand day on Monday without a mask before the state government regulations changed due to South Australia's COVID-19 status.

That same day defence counsel Lucy Flanagan was required by court staff to don a mask because she had recently travelled to Victoria.

Acting Justice Martin told the jury that it was possible he may "suddenly rip it off" if he tired of it.

A spokesperson said Acting Justice Martin has also had three recent COVID checks, including July 17 2021 with all tests producing negative results.

The Judge had also not visited any high risk premises (hotspots) in South Australia during the relevant period.

The acting judge was previously Chief Justice of the Supreme Court of the Northern Territory from 2004 - 2010 and has been a judge of the Supreme Court of South Australia.

He was made an Officer of the Order of Australia in the Queen's Birthday Honours of 2011.