HOUSTON -- A cancer researcher in Texas was convicted Friday of aggravated assault for poisoning her colleague, who was also her lover, by lacing his coffee with a sweet-tasting chemical found in antifreeze.

Dr. Ana Maria Gonzalez-Angulo, 43, a breast cancer doctor based at Houston's famed Texas Medical Center, had been involved in a sexual relationship with her fellow researcher, Dr. George Blumenschein.

Prosecutors told jurors that Gonzalez-Angulo was a devious and diabolical person who became obsessed with Blumenschein. They said the affair turned into a "fatal attraction" and she poisoned him with ethylene glycol after Blumenschein spurned her in favour of Evette Toney, his live-in girlfriend of 10 years with whom he was trying to start a family.

Blumenschein told jurors that he became sick Jan. 27, 2013, not long after he and Gonzalez-Angulo had been intimate, and that he immediately suspected his lover of spiking his coffee. Witnesses testified that Gonzalez-Angulo had access to ethylene glycol at the University of Texas M.D. Anderson Cancer Center where she and Blumenschein worked.

Gonzalez-Angulo's attorneys argued that other people, including Toney, might have been responsible for the poisoning, an allegation that Toney has denied. Toney says she and Blumenschein are working on their relationship.

The defence team also noted a prosecution expert's testimony that Blumenschein could have ingested the poison two days earlier.

The trial, which began Sept. 15, was filled with plot twists straight out of a soap opera, including prosecutors' claims that Gonzalez-Angulo lied about being attacked outside her home in an effort to get Blumenschein to leave his girlfriend. Prosecutors also said Blumenschein secretly recorded calls in which he tried to get Gonzalez-Angulo to confess to poisoning him.

Blumenschein said he delayed reporting his suspicions to authorities for fear that Gonzalez-Angulo would try to hurt him or Toney.

He told jurors he now has only about 40 per cent of his kidney function.

Jurors are set to hear testimony in the trial's punishment phase before deciding on a sentence. Gonzalez-Angulo faces up to life in prison.