A High Court judge has been told about the "massive" love of one Candy brother for the other.
Christian Candy and his older brother, Nick, are jointly attempting to fight off a claim by property developer Mark Holyoake for £132 million damages.
The claim is against both Christian and Nick, who are best known for creating the luxury One Hyde Park apartment complex in Knightsbridge, central London.
Mr Holyoake, 44, alleges the brothers subjected him and his family to a campaign of intimidation, including threats against his then pregnant wife, Emma, after a property deal went wrong.
Mrs Holyoake has told the court links between the Candy brothers and several high-profile figures who died in mysterious circumstances "made me fear for my husband's life".
She described Christian as "aggressive and controlling" and said Holly Valance, Nick's actress wife, who had been a friend, had described to her how her husband was bullied by his young brother.
The former Neighbours star had confided to her how Nick had once been so distraught by Christian's behaviour he had "lain down in a foetal position on the floor of a hotel room and wept inconsolably".
But on Thursday Christian Candy told the court at the start of at least three days of cross-examination: "I love my brother massively."
Mr Holyoake borrowed £12 million from Christian Candy's company CPC in October 2011 to help him buy Grosvenor Gardens House in Belgravia, London, to convert into a luxury property for a substantial profit.
He gave evidence that he eventually paid back more than £37m on the two-year loan and had to sell up at a loss of £100m in potential profits after incurring millions of pounds in legal fees and other costs.
He is accusing the Candy brothers of being involved in a conspiracy against him to obtain Grosvenor Gardens House at a lower value, or to extort "very significant" sums of money from him and his company, Hotblack.
Roger Stewart QC, appearing for Mr Holyoake, suggested to Christian Candy that he and Nick were jointly involved in the running of the highly successful Guernsey-registered company CPC.
The QC said: "If, contrary to your evidence, CPC has always been a partnership between you and your brother, enormous sums of (UK) tax have unlawfully been evaded."
Mr Candy replied: "If Nick was a co-owner, which he has never been, then yes I believe that money would be owed to the Revenue."
He told the court there was no partnership agreement with his brother and CPC "is 100% owned by me".
Mr Candy said in a witness statement that, before setting up CPC, he and Nick had run the luxury interior design company Candy & Candy Ltd (C&C), but in 2011 he had resigned and sold all his shares to his brother, who was now 100% owner of that company.
However, CPC and C&C had often worked together on development projects.