An online steroid dealer who sold toxic slimming pills that killed a bulimic student has been found guilty of manslaughter.

Eloise Parry, 21, from Shrewsbury, died in hospital on 12 April 2015 after taking eight tablets containing dinitrophenol (DNP).

Bernard Rebelo, 31, from Gosport in Hampshire, was found guilty at Inner London crown court of manslaughter and placing unsafe food on the market. He will be sentenced on Friday.

While giving evidence during the trial, Rebelo admitted he had sold DNP to Parry. He told the jury he had included a warning on his website that the substance was not for human consumption.

Rebelo’s girlfriend, Mary Roberts, 32, was cleared by the jury of one count of money laundering after she was accused of transferring £20,000 for and on behalf of Rebelo.

Roberts said she had never seen capsules for making pills where she lived and if she had she would have asked Rebelo why they were there. She said she had taken little interest in details of a business Rebelo had set up to sell “muscle-enhancing supplements and protein shakes”.

The couple wept in the dock as the verdicts were delivered on Wednesday afternoon, with Rebelo asking the judge: “Can I see my daughter?” Roberts could be heard crying as the couple hugged one another.

Parry’s sister, Rebecca, 19, said in a statement read out during the trial that Eloise had been focused on losing weight. She said that in the months leading up to her death, her sister had struggled more and more with her eating disorder.

“The diet pills she had taken had made her lose a drastic amount of weight but she still wanted to be slimmer,” she said.

She recalled that her sister had struggled with her mental health during her teenage years and had been diagnosed with bulimia and borderline personality disorder.

Jurors were told that Parry started taking the chemical in pill form in February 2015 and soon became addicted. In the weeks before her death she was admitted to hospital numerous times because of side-effects of DNP, her sister said.

The trial heard that DNP could cause multiple organ failure, hypothermia, nausea, coma, muscle rigidity, cardiac arrest and death. Depending on a person’s body weight, as little as 200mg of DNP can be lethal.