Rebecca Zahau, who died back in 2011

The family of a woman who was found dead in a San Diego mansion have launched a $10million civil case against her millionaire boyfriend's brother accusing him of her murder.

Rebecca Zahau was found naked and hanging from a balcony at the mansion owned by her boyfriend Jonah Shacknai, the CEO of a pharmaceutical company.

It happened just two days after Shacknai's six-year-old son Max from a previous marriage had fallen to his death from a second-story balcony at the mansion.

The family claim that Mr Shacknai's brother Adam, a tugboat operator from Tennessee, blamed her for the tragedy because she was responsible for the boy at the time.

They allege that he killed Rebecca in revenge and have filed a wrongful death lawsuit.

It is claimed that he was the only other person in the house when she died and also that Rebecca's legs and arms had been bound.

Investigators recorded her death as suicide in 2011.

The trial started on Monday and jurors were selected for the civil case.

Forty-five potential jurors spent Monday filling out questionnaires.

They will return Tuesday with their filled-out and questioning will continue.

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The family of a woman who was found dead in a San Diego mansion (pictured) launched a $10million civil case against her millionaire boyfriend's brother accusing him of her murder

Zahau's was found hanging from this second-floor balcony (left). It happened just two days after Shacknai's six-year-old son Max (right) had fallen to his death from a second-storey balcony at the mansion

Max Shacknai, aged six, was in Zahau's care when he plunged to his death off a staircase and was found on the first floor, next to a shattered chandelier (pictured)

Other views of the staircase that allegedly claimed Max's life at his family home

If all runs smoothly, the jury could potentially be sat by the end of the day with opening statements expected as early as Wednesday.

The family of Zahau filed the $10million wrongful death suit claiming that she was murdered in 2013 - almost two years to the day after her death.

Authorities ruled Rebecca Zahau's death July 13, 2011 a suicide.

It was the second bizarre tragedy in days at the multimillion-dollar Spreckels Mansion in Coronado, California, which belonged to Zahau's boyfriend, Jonah Shacknai - the twice-divorced CEO of Medicis Pharmaceutical, which makes Restylane and Dysport for treating facial wrinkles.

Just two days earlier, six-year-old Max Shacknai, Jonah's son by his second wife, Dina, fell off a staircase in the home and was found mortally injured next to a shattered chandelier. He died days later in the hospital.

Rebecca Zahau was found naked and hanging from a balcony at the mansion owned by her boyfriend Jonah Shacknai, the CEO of a pharmaceutical company. They are pictured here together

Zahau was the only adult at the house at the time of Max's fatal fall. His father was at the gym

Implement of death: A red rope is seen tied to the leg of a bed on the second floor of the mansion. The other end of the rope was tied to Zahau's neck

The rope that Zahau allegedly used to hang herself is seen hanging over the balcony railing

A knife is seen in the second-floor bedroom after Zahau's suspected suicide

Zahau was the only adult present at the time of the boy's injury.

Zahau's sister and her mother are alleging in the lawsuit that Zahau did not kill herself - but was murdered.

The court filing doesn't provide any specific evidence, but alleges 'defendants planned and prepared to batter and murder Rebecca and did thereafter brutally, and with malice aforethought, stalk, attack, choke, bound and hang her.'

Other Shacknai relatives were implicated by the Zahaus in 2013, including Max's mother Dina and her sister Nina Romano, but last year the family's attorney Keith Greer dismissed the sisters from the lawsuit and publicly apologized to them, reported Town&Country at the time.

Jonah Shacknai, the billionaire founder of Arizona-based Medicis Pharmaceutical, which he sold in 2012 to another company for $2.6billion, is not named in the lawsuit.

Shacknai and Zahau, an immigrant from Myanmar, had been dating since 2008.

An extensive investigation by the San Diego County Sheriff's Office found no criminal wrongdoing in either death and no charges were ever filed.

A San Diego Sheriffs Department diagram showing the northeast bedroom at the Spreckels Mansion on the day of Zahau's death, alongside scene photos

A diagram of the Spreckels Mansion courtyard on the day of Zahau's death, alongside photos from the scene of the incident

The family claim that Mr Shacknai's brother Adam (pictured) blamed her for the tragedy because she was responsible for the boy at the time

Adam Shacknai was staying in a guesthouse at his brother's mansion (pictured)

Authorities said Zahau killed herself because she was distraught over the fall that Shacknai's son suffered on her watch.

Max's death also was ruled accidental.

Adam Shacknai, then aged 48, was staying in a guesthouse at his brother's historic Spreckels Mansion on Ocean Boulevard at the time of Zahau's death, the U-T reported.

Adam told police he found Zahau hanging naked from a red rope from a second-story balcony at the mansion, and cut her down. The other end of the rope was tied to the leg of a bed.

Her hands were bound behind her back, her feet were bound and a T-shirt was wrapped around her lower face.

In a deposition, Adam said he felt sorry for Rebecca after Max's fatal fall, and that on the eve of her death he told her she could seek him out if she wanted to talk.

He then retired to the guesthouse, took an Ambien and went to sleep. Rebecca spent the night alone in the 27-room mansion.

Early the next day, Adam walked over to the main house to get a cup of coffee and found Zahau's naked and bound body hanging from the balcony, after which he placed a 911 call.

Lavish property: The remodeled mansion was sold last month for $9million to the owner of a private aircraft company in Utah

Officers who responded to the scene found a pair of knives, black paint, brushes, and a cryptic message painted on the door that read: 'She saved him can you save her.'

Dina told Town&Country last year that she and Jonah were at Max's bedside as he lay dying at the hospital when the call came in about Rebecca's suicide. She recalled asking her ex-husband why she would do that, he allegedly mimicked the motion of stabbing himself in the stomach and replied, 'Asian honor.'

Dina Shacknai told the magazine she is convinced that Max's and Rebecca's deaths are intertwined, but she she does not believe that the woman had attacked the six-year, nor does she believe that she then died of a suicide, nor that Adam was the culprit.

In both cases, Dina Shacknai suspects that there was someone else whom police never investigated.

The remodeled Spreckels Mansion was sold last month for $9million to the owner of a private aircraft company in Utah.