A man who allegedly altered a text message to say he had returned a positive Covid-19 test result, before sending it to several other people, has appeared in court.

Devon Graham Stock, 27, who court documents state is a butcher living in Cambridge, is facing a single charge of altering a document - namely a text message from the Ministry of Health - with intent to cause loss.

The charge alleges the offending happened in Ōtorohanga, on September 22.

It carries a maximum penalty of 10 years in jail.

Stock appeared in Hamilton District Court on Monday, where he was remanded without plea to next appear on October 14.

He had attempted to appear in the same court on Friday, but was turned away at the door by security staff because he told them he had recently been in the Auckland area.

In a statement sent to media, police allege Stock edited an official text message informing him he had returned a negative Covid-19 test result to read that he had returned a positive test result.

He then contacted a number of people claiming he had returned a positive test result.

Stuff understands his actions resulted in at least one business in the Waikato shutting down operations on Wednesday night, before later being told the seemingly legitimate text was fake.

Waikato West area commander Inspector Will Loughrin says police were made aware of the incident after one of these concerned people contacted them.

The Ministry of Health confirmed Stock undertook a Covid-19 test on September 20, which returned a negative test result on September 22, he says.

-Stuff/Mike Mather.