Police arrested Vincent Stanford, 24, a cleaner at Leeton High School, at a house on Maiden Avenue in Leeton, in the NSW Riverina, about 7.30pm on Wednesday, and took him to Leeton police station for questioning.

Police said on Thursday morning he was charged with the murder of Ms Scott, 26, a popular drama and English teacher from the school. 

Mr Stanford is expected to appear before Griffith Local Court on Thursday.

Fairfax Media understands police have seized the phone that contains photographic evidence.

Police began to home in on Mr Stanford on Wednesday after allegedly finding holes in his alibi. When they questioned him they allegedly found a number of items linked to Ms Scott's death.

A senior manager of the cleaning company that employs Mr Stanford said he had undergone standard criminal checks before he was employed.

Colin Joss & Co cleaning division manager Fleur Dooley said the suspect had worked for the Albury based company since October 2014.

Ms Scott was last seen at the school on Easter Sunday, six days before she was due to marry her partner of five years, Aaron Leeson-Woolley.

A NSW police spokeswoman said police had not found Ms Scott's body. Her car, a red Mazda 3 sedan with registration BZ-19-CD, was spotted by a helicopter on Thursday morning in open fields about eight kilometres outside Leeton.

Police also are appealing for anyone who has seen an older model white Toyota Hilux space-cab two-wheel-drive, with a canopy over the back, travelling in Leeton or surrounding towns since Sunday, to contact them.

On Wednesday, Ms Scott's sister, Robyn, told Fairfax Media that her sister was incredibly excited about her upcoming wedding, due to take place on Saturday in the central western NSW town of Eugowra.

More than 100 guests were due to attend the wedding, including family who had travelled from overseas.

"I spoke to her on that Saturday night, and she was over the moon, she was so excited. She had been to Griffith that day shopping and getting ready for the honeymoon," Robyn said.

Robyn said her sister had gone to Leeton High School on Easter Sunday morning to prepare lessons for a replacement teacher who would take over her English and drama classes while she was on honeymoon in Tahiti.

She said that, at 12.59pm on Easter Sunday, her sister sent an email to the bus company that was due to take wedding guests to the reception venue on Saturday. In the email, Ms Scott confirmed she had paid the final deposit into the bus company's bank account.

That was Ms Scott's last known action.

Police formed Strike Force Gundibri to investigate Ms Scott's disappearance.

Police said that, on Wednesday night, officers attended a home on Maiden Avenue, where they spoke to two residents.

About 7.30pm, another resident of the home – a 24-year-old man – arrived at the property and was arrested and later charged with one count of murder.

Devastating news: Mayor

Paul Maytom, the mayor of Leeton Shire, said news of Ms Scott's suspected murder was "absolutely devastating".

"I'm still trying to come to terms with it," he said on Thursday. 

"The last few days everyone's been talking about it in the town. For her to mysteriously disappear like that, everyone was hoping she was going to be found, and found alive. We didn't know what could have happened.

"I was not considering it would end up like this. We have a small community, most people know each other or know the families in our shire, and to have someone like Stephanie, who's such a well-liked person, just about to be married next weekend ...  it's just devastating."

Cr Maytom said Ms Scott's fiance had been "absolutely worried sick" since her disappearance.

Neighbours shocked

Neighbours on Maiden Avenue were shocked to discover police on their street after news of Ms Scott's disappearance had overwhelmed the small town.

"You just don't expect anything like this in this area," said Janice Cameron, who has lived for 34 years next to the house were Mr Stanford was arrested.

"It is a very quiet neighbourhood, we don't have any trouble."

Mrs Cameron said that Mr Stanford had moved into the area about a year ago, and that the resident in the house mostly kept to themselves. 

One neighbour, who asked not to be named, described the accused's household as "beautiful people".

"They would always say hello in the street, just like everyone does when you live in a tiny town like ours."

She said she was extremely surprised to learn that Mr Stanford had been arrested in connection with the murder. 

- with Eryk Bagshaw SMH