Mark Sheridan Waden, 50, allegedly killed Priscilla Brooten and buried her body in a trench before dumping it at a Brisbane rubbish tip almost a year later.
Ms Brooten, a 46-year-old US citizen who was staying in Australia without a valid visa, vanished from the home she shared with Waden in Brisbane's northern suburbs in July 2018.
A Brisbane Supreme Court jury heard testimony from several of Ms Brooten's friends on Monday during the second week of Waden's murder trial.
Laetitia Penfold said she met the American for yoga and Zumba classes three or four times a week up until June or July 2018.
"She started not coming to the gym ... everyone was asking me where she was, all the ladies from the gym," Ms Penfold said.
She also sent a joking text message to Ms Brooten, asking: "Where are you, bitch?"
"Did you get a reply back?" crown prosecutor Andrew Walklate asked.
"No, I called and got no reply," Ms Penfold told the court.
The jury heard Waden, who was a Zumba instructor, went to the gym classes after Ms Brooten stopped attending.
Ms Penfold said she spoke to Waden after one session and asked him where Ms Brooten had gone.
"He said immigration was looking for her and she ran away," she said.
Waden also said he did not know where Ms Brooten was, the court was told.
"He told me she was taking money ... $70,000 that she stole from him pretty much," Ms Penfold said.
Waden's Zumba classes became "more aggressive" in a military style after Ms Brooten stopped attending, Ms Penfold said.
Vicki Le told the court she called Waden after he and Ms Brooten "unfriended" her on Facebook.
"He said I don't have anything to do with Priscilla anymore," Ms Le said.
"He said there was an incident where nasty people were after her and she took off. She owed them money and owed him money."
Waden allegedly told her Ms Brooten was frightened of the people she owed money to but wasn't scared of him.
Rebecca Astier gave evidence Waden told her and several others that Ms Brooten left him and he did not know her whereabouts.
"He said she had been in Australia illegally and the border patrol were looking for her," she said.
"He said she had cost him money and was being secretive."
The jury also heard pre-recorded testimony from Waden's former colleague, Desiree Hatzipapas, who said she formed a secret relationship with the accused shortly before Ms Brooten vanished.
Ms Hatzipapas said Ms Brooten left his home after an argument that resulted in police being called.
"He texted me saying I've completely closed her off," she said.
Waden offered her clothes and makeup that he said Ms Brooten had left behind, the court was told.
The trial continues.
