Rob Packham, who stands accused of murdering his wife Gill, on Monday gave domestic explanations for the presence of blood in different parts of their Constantia home.
Detectives had swept their home in Riesling Road for clues following Packham's arrest, after his wife's charred remains were found on February 22, 2018, in the boot of her burnt-out car at the Diep River train station in Cape Town.
He has pleaded not guilty to the murder of his wife and a charge of obstruction of justice.
Investigating officer Sergeant Ivan Sonnenberg told the court that blood had been found in the garage, where the couple had parked their BMW and Audi Q5, and on the inside front door handle of the driver's side of Rob's Audi. Both blood specimens belonged to Gill.
Blood found in and around the basin of the en suite bathroom was found to belong to Rob.
Sonnenberg said the accused had never explained the presence of his or his wife's blood.
Taking the stand in his defence on Monday, Packham listened as his lawyer, advocate Craig Webster, said that Gill's blood had been found on the garage door, a fertiliser bag, his inside car door handle, and a piece of paper.
Packham said his wife had taken a load of recycling to the dump a few days before her disappearance.
"She had been hounding me about it for some time... she had several bags in the boots of my car." Bags with recycling were also on the garage floor.
She told him she was using his car to go the dump.
"In the process of moving bags from her car to my car, she cut her hand," he said, adding that it must have been on a broken glass or broken bottle.
He said his sister had seen Gill with a plaster on her hand.
Explaining the blood on the fertiliser bag, he said his wife had been "an extremely enthusiastic gardener" and could have pricked herself on a thorn or cut herself while busy with pruning clippers.
"She mentioned it to me when she got home and had put a number of plasters on it."
As for his blood under the basin and on a towel or bath mat, he said he cut himself a few times a month while shaving.
"If a drop of blood was on the bath mat or towel, and it was my blood, then I could say with absolute certainty that that is how it got there. I have a little mole or growth on my neck which has a habit of getting itself nicked."
He said his wife had wanted him to get an electric razor to solve this problem.
Asked if he was in any way involved with his wife's murder or the disposal of her body, he adamantly denied this.
"Absolutely not, my lady," he said.
The court earlier heard that Packham had arrived at his home the day after his wife's disappearance to find about four police vehicles and six or seven officers in front of his home, with the road cordoned off with tape.
He said he was ignored while police officers took photos of his Audi Q5 with their phones. He said an officer had taken his cellphone from his hand and demanded the pin, which he had given.
"I was not allowed to go into my house. I was told to stay in the garage. Eventually I was told to get into one of the police vehicles to give a statement [at the station]," he said.
"It was not a pleasant experience," he said twice during his recollection of this moment.
Packham was adamant that Sonnenberg had suggested to him at the police station that he should take a lie detector test, which he said he was happy to do.
"He laughed and said he had seen grown men cry taking polygraphs. He then looked at me and said, 'I don't think it's necessary'."
Asked about this during his testimony, Sonnenberg had said he could not remember everything that happened then.
The trial continues.