Xuan Yang has filed a petition in B.C. Supreme Court asking that any DNA samples of murder victim Gang Yuan be preserved.
The victim was found cut into more than 100 pieces last month, a lawyer for the estate told media shortly after the death on May 2.
Li Zhao, 54, who is married to the victim's cousin, has been charged with second-degree murder.
Yuan's estate is estimated to be worth $50 million, the court petition said.
The woman's petition said Yuan died without a will or any other children with a claim to his estate so his brother stands to inherit the fortune by disproving her daughter's claim.
She alleged the brother, Qiang Yuan, warned her not to come to Vancouver from China because her safety would be in jeopardy, then said he would arrange a DNA test comparing his brother's remains with the daughter.
Yang's petition claimed the test was inconclusive and that she cut off contact with the brother after her lawyer discovered he supplied some remains directly to a lab.
"(The brother) then called (Yang's) mother in Beijing and told her it was urgent he get hold of (Yang) and confirmed to her that he had ordered the deceased's remains to be cremated," the petition says.
None of the allegations has been tested in court. A lawyer for Yuan's estate, Mark Thompson, declined to comment and referred calls to another lawyer, Chris Johnson, who did not immediately respond.
The petition said that if the deceased's remains have been cremated, then the only intact sample of his DNA would be with the BC Coroners Service or the Vancouver Police Department.
Yang said in her petition that she met the murder victim in Beijing and they spent several weeks together on vacation in Las Vegas, Miami and Mexico.
She said she gave birth in California in March and the hospital birth certificate declares Yuan as the father.
Yang said she has filed 269 pages of text messages in which she and Yuan discuss the birth of the child, his intention to marry her, his wish that she not get an abortion and exchanges of ultrasound images.
"The deceased not only acknowledged the infant as his offspring during his lifetime, he flew to Beijing to meet (Yang's) parents, paid for the petitioner to come to Vancouver while she was pregnant and live with him and flew her to Los Angeles," the petition said.
A lawyer for Yuan's estate has said his West Vancouver home was in the name of the accused, Zhao, and his wife for tax reasons.
Zhao, whose daughter starred in a reality series called "Ultra Rich Asian Girls," was also charged with interfering with a body in connection with the slaying.
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