Police divers have pulled a laptop from an irrigation canal outside Leeton during their search for the body of missing teacher Stephanie Scott, after witnesses saw a man dump something in the water on Easter Monday.

The computer was pulled out of the two-metre deep canal on Leeton's outskirts this morning.

Ms Scott was allegedly murdered on Easter Sunday by Vincent Stanford, a cleaner from her workplace, Leeton High School.

The 26-year-old English and drama teacher, was last seen at the school on Myrtle Street about 11:00am on Sunday, police said.

Police divers search for the body of murdered teacher Stephanie Scott in Leeton. ( ABC News: Nick Dole )

Police turned their sights to the waterway after a witness reported seeing a man throw something in the irrigation canal on Monday.

Brendan Lyons has a large shed across the road from the canal and said other people on the property that day had also spoken with police.

He said a man ran up the bank towards the canal and had something in his hand, which he threw into the water.

"It was close to 4:00pm [Easter Monday]," Mr Lyons said.

The NSW Government promised to make available any police resources needed to help find the body of Ms Scott.

Premier Mike Baird said he felt for her family as the search continued.

"I'd want to remind that whole community and that family that we stand beside them," he said.

"That is not something that they should be doing alone, and I thank the community for already showing so much support for that family and we'll do anything we can to support them."

Search to be extended beyond Leeton

Griffith local area commander Superintendent Michael Rowan said police were also still asking the public to come forward with information about the whereabouts of a white Toyota Hilux between Sunday and Wednesday.

"We have the accused's car," he said.

"We are really interested in people who might have sighted it between Sunday lunch time and Wednesday night."

Superintendent Rowan said the search had been extended beyond the town of Leeton and police on trail bikes would also join the operation.

"At this stage it's a fairly wide geographic area," he said.

"It may extend, or again it might narrow, depending on what information we get from the public and others."

Police are appealing for anyone who saw this Toyota Hilux between Sunday and Wednesday to contact police. ( Supplied: NSW Police )

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