Never-before-seen footage shows Erin Patterson calmly questioned by police at the table where three of her relatives were poisoned.

The first released footage shows Erin Patterson inside her Leongatha home in Victoria on August 5, 2023, a week after the 50-year-old served a beef Wellington laced with death cap mushrooms.

WATCH THE VIDEO ABOVE: Vision of Erin Patterson grilled by police released.

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The footage was tendered as exhibits during Patterson’s trial, but was only released to the media on Monday.

Seated at the same dining table where she hosted the deadly lunch, Patterson appears composed as she speaks with a detective, even handing over what police later suspected was a dummy mobile phone.

“Thanks for your patience today, Erin,” Detective Sergeant Luke Farrell says.

“We’re completing our search. The only outstanding item is that mobile phone that you’ve got there, so I’ll seize that from you.”

Farrell then asks Patterson for the PIN to her phone, and she offers two possible combinations, saying she can’t remember which one is correct.

The phone later unlocked without a PIN code.

“Makes your job easy,” Patterson says.

“We were later to find out that the police believe there was a second mobile phone, so perhaps that helps to explain why she is so calm,” criminologist Dr Xanthe Mallett said.

The phone, a Samsung Galaxy A23 nicknamed Phone B, was one of four devices owned by Patterson.

Investigators believe it was factory reset once before and then remotely wiped again after it was seized.

Prosecutors told the court the Samsung device contained no significant data.

Meanwhile, the main phone Patterson used before the deadly lunch, known as Phone A, was never found.

Another piece of footage released on Monday shows Patterson dumping a food dehydrator she used to dry the death cap mushrooms.

She attempted to dispose of it four days after the lunch, but police later recovered it, with samples of the deadly fungi still found on the trays.

On July 7, Patterson was found guilty of murdering her husband Simon Patterson’s parents, Don and Gail Patterson, and Gail’s sister Heather Wilkinson, as well as attempting to murder Heather’s husband, Ian Wilkinson.

The mother-of-two maintained her innocence throughout the trial, claiming the poisonings were accidental.

She is yet to be sentenced, and remains in custody at the Dame Phyllis Frost Centre, a maximum security prison for women in Melbourne’s western suburbs.