Mervyn Jacobson, 72, of Brighton, told a Supreme Court jury his daughter, Tamara Newing, had been a day trader buying and selling shares in his biotech company, Genetic Technologies, when he became aware she was being investigated by the authorities.

"It was all crazy, with hindsight," Dr Jacobson said when giving evidence during his trial on charges of stockmarket manipulation.

Asked by Crown prosecutor Jeremy Rapke, QC, if he had feared in late 2006 that his daughter might have committed a criminal offence, Dr Jacobson said: "It doesn't come to my mind that it's a criminal offence.

"It comes to my mind my daughter has done something wrong, whatever wrong means.

"And that she might be in trouble. Trouble or - my definition of wrong is even broader than the criminal.

"There is a certain good faith, honesty that I conduct my life by, and I would hope she conducted her life the same way ... we act in good faith and I was concerned that there was something going on and I'm sure I would have met with her and discussed it, preferably face-to-face."

When Mr Rapke put it to Dr Jacobson that he had known his daughter had been manipulating his company's share price during 2006 because it was at his request, he replied: "That is false ... what you are saying is very offensive and false."

"She'd been doing a lot of things that make no sense to me, but I was not involved and I was not consulted and I was not aware of it."

Dr Jacobson said he did give his daughter $1.55 million but it was a gift, not to buy shares in his company to artificially inflate the price.

"There was no condition on what she had to do with it [the money] from me at all.

"I was not interested in whether she bought any shares ... she could buy, she could sell, she could buy a house, go on a trip, go gambling. I was giving her money like I promised to give her and there was simply no strings attached and there was no requirement for her to ever tell me what she did with it."

Dr Jacobson has pleaded not guilty to 35 charges of conspiracy to manipulate the market and fund transactions to create an artificial share price between May and November 2006.

Mr Rapke has told the jury the case was about price-fixing.

Dr Jacobson had been involved in research and other activities involving human genetic material before his company, Genetic Technologies, invented a method to obtain valuable information located within what is called the non-coding DNA of all species.

Shares in Genetic Technologies were listed on the Australian Stock Exchange (ASX) and Dr Jacobson controlled more than 40 per cent of the company's shares, totalling over 150 million shares.

The Crown case alleged Dr Jacobson's daughter and her second husband, Geoffrey Newing, from Toorak, acted illegally and were heavily involved with Dr Jacobson in manipulating the price of Genetic Technologies shares on the ASX.

Mr Rapke said much of Dr Jacobson's wealth was tied up in the company and his financial stability was dependent on the company's success and its share price.

So when the share price began to fall and Dr Jacobson began receiving margin calls on a $11.4 million loan with Opes Prime, Mr Rapke said Dr Jacobson gave more than $1.55 million to his daughter.

The prosecutor said Tamara, her husband and two stockbrokers then used the money to buy Genetic Technologies shares on the ASX to maintain the price at an artificially high level.

Defence barrister Joshua Wilson, QC, told the jury very large sums of money did pass between Dr Jacobson and Tamara but the cash was a gift.

The trial, before Justice Stephen Kaye, continues.