Queensland police are excavating the front yard of a home in Brisbane’s north where a missing American woman lived with her partner.

Priscilla Brooten was formally reported missing in December last year but the 46-year-old was last seen in July, in Bracken Ridge.

The police confirmed that the cold case disappearance was now a homicide investigation.

They were also forensically examining the house and a car at the property.

“I can confirm there’s a 42-year-old gentleman from Bracken Ridge who is assisting police with their inquiries,” detective senior sergeant Michael Hogan told reporters in Brisbane on Saturday.

The pair had been in a relationship for a year before Brooten disappeared and police say the man failed to report her missing.

Brooten has been described as an outgoing and friendly yoga and Zumba enthusiast.

Police dogs had pinpointed a narrow strip of land in the front yard alongside the driveway where the search was concentrated.

Brooten’s blue Volkswagen Golf hatchback was found abandoned in Bunton Street, Scarborough about 9pm on Friday, 6 July 2018, and police had urged people who might have seen it to come forward. They believe the car was moved from Bracken Ridge.

Hogan said Brooten was a keen gamer and appealed to her friends in the online gaming community to come forward with information.

“It is certainly a possibility that we are keen to explore,” he said.

“They might not have even known she was missing.”

Brooten’s mother and daughter live in California and have been kept up to date with the search.

They first contacted the police in July with concerns about Brooten’s whereabouts.

The police are yet to lay any charges.