Mario Santoro had been living with Haddad until she asked him to move out a few weeks before her death

This article is more than 2 years old

This article is more than 2 years old

The man police are treating as a person of interest in the murder investigation of 38-year-old Cecilia Haddad, had been looking for work in Brazil in a bid to return home, a former colleague has said.

Mario Santoro had been living with Haddad until she asked him to move out of her Ryde home, on Sydney’s north shore, just a few weeks before her body was found in the Lane Cove river.

Australian investigators have been working to track down her former lover, Santoro, who flew home to Rio De Janeiro last weekend.

Cecilia Haddad: family devastated as police seek Brazilian murder victim's former lover Read more

Alvaro Ribeiro, who owns a vaccination clinic in Rio, told the Guardian he had spoken to Santoro in March over the WhatsApp messaging service. The two had previously worked together in the health industry, but not seen each other in person since 2011, Ribeiro said.

“I was director One Health and he was a director at United [Health Group]. We met again there and became friends.”

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He said he last talked to Santoro, who he described as “polite” and from an educated, upper-class family, on 19 March, after Santoro contacted him on LinkedIn and said he was looking for work in Brazil after spending time abroad.

“[He said]: ‘I am very far away, I am unhappy, can you give me a tip [of any work].’ I said: ‘It is difficult in Brazil, but there are some important American consultants, with your profile you could fit,’” Ribeiro recalled.

“He said he was wanted to come back, he wants a job in Brazil and work. He is very far from family. He is very concerned with his family, he has young children, he is separated.”

Ribeiro said Santoro told him he went first to Malaysia and then Australia, but didn’t mention setting up a company with Haddad. Ribeiro said he didn’t ask Santoro why he wanted to move home, and assumed it was work-related.

Facebook Twitter Pinterest Mario Santoro had been living with Cecili a Haddad until she asked him to move out. Photograph: Facebook

In a second conversation, Ribeiro said he had tried to reach Santoro but his WhatsApp number was disconnected.

Brazilian authorities are assisting Australian police in the effort to locate Santoro.

On Friday Australia police dive squads returned to a section of the Parramatta river, beneath the Gladesville Bridge, searching for a set of car keys investigators believe may be crucial evidence.

The Guardian understands police are operating on information from the public in their search of the area on the opposite side of the Woolwich peninsula to where Haddad’s body was found.

While it was initially thought she had accidentally drowned, police are understood to be treating her death as murder.

Haddad had lived in Australia for more than 10 years. In that time she worked as a mining logistics executive in Western Australian and as a consultant for the Newcastle-based Australian Rail Track Corporation.

Her brother João described his younger sister as a dedicated and hard worker who had graduated in business and logistics at Rio’s upscale Pontifical Catholic University, where she later mastered in logistics. She had also studied ballet at the city’s municipal theatre.

“She was a very beautiful girl, she danced ballet,” he told Guardian Australia. “She was very intelligent, very happy, very loving.”