The court heard that the victim discovered a “gloopy” substance at the bottom of her cup after throwing out the contents when she became concerned by the taste.
Prosecution barrister Richard Posner told the court that the victim first began to believe that there was “something not right” about the drinks in September 2021 - but had been worried for much longer, the Daily Mail reported.
Recalling when the victim first began to have doubts in 2020, Poser said she “took a sip of her drink and spat it out into the sink.
“It didn’t taste right. It tasted salty. She tipped the remainder into the sink and saw a thick, gloopy substance go into the sink.
“She just knew it was something that shouldn’t have been there. She did not for a moment think it could have been semen.”
She reportedly told others about the strange taste and began to tip away drinks that Chapman made for her.
After around half a dozen other incidents, Posner said the woman says she “realised the reality” of her situation in September 2021 when she saw the doctor with a plastic specimen container that had “no business being there”.
She waited another week and saw him with what she believed was another specimen bottle as he made her another refreshment.
She tipped out the drink and took photos of the foul residue, also taking samples which were then frozen and handed to police.
Subsequent DNA testing showed a match to the defendant, the Mail reported.
Chapman was later arrested at his workplace, telling police he was “shocked” by the accusation and claiming a medical condition may be behind the contamination.
He claimed that prostatitis meant that he lets out semen while defecating and some may have remained on his hands.
Virgina Cornwall, acting for the defence, said that Chapman had no sexual interest in the victim.
“He did not tamper with her coffee - and can only assume someone else did as a prank,” Cornwall told the court.
Cornwall admitted that the sample of coffee contained fluid from her client, it was a “by-product of defecation and not sexual in nature”.
The trial continues.