POLICE allege the stabbing of an elderly woman and her son in Hervey Bay on Friday was a freak, unprovoked attack during what should have been a routine online sale.

The man allegedly responsible has fronted court charged with attempted murder.

Speaking to reporters on Monday, Detective Sergeant Mick Polit said a man had allegedly tried to slit the 82-year-old woman's throat while she ate her breakfast on the balcony, unaware something was wrong.

He said initial investigations suggested NSW man Adam Curtis Brown had purchased a printer from the woman's 50-year-old-son costing about $5000.

Police at a crime scene in Mungara Court, Wondunna.
Police at a crime scene in Mungara Court, Wondunna. Alistair Brightman

"It appears the accused has been liaising with the victims in relation to buying a 3D printer," Sgt Polit said.

"We still haven't got to the exact details of what occurred, but it's a vicious attack upon two elderly victims."

Sgt Polit said Brown, who lives in Port Macquarie, was in south-east Queensland for other reasons before driving to Hervey Bay for the purchase.

"What's transpired from there has resulted in the charges today," he said.

The woman was released from hospital on Sunday and taken to the Hervey Bay police station to provide a formal statement.

Her son last night remained in a Brisbane Hospital in a serious condition.

Sgt Polit said the woman was "very traumatised" from the ordeal.

"She was not involved in the initial altercation between her son and the man, she was sitting outside her house eating her breakfast," he said.

"The male tried to slit her throat."

Mr Brown fronted Hervey Bay Magistrates Court on Monday morning charged with two counts of attempted murder.

No bail application was made.