A couple who founded a charity to save Chinese tigers before their marriage broke down have returned to court for another round of litigation in their multi-million-pound legal fight.

Chinese conservationist Li Quan and estranged husband Stuart Bray, a banker from America, launched the Save China's Tigers project more than a decade ago.

But for three years, they have been embroiled in a legal battle and a judge has warned them the money they are fighting over could end up in lawyers' pockets.

Li Quan will be back in court over a three-year long legal dispute with her estranged husband, Stuart Bray

Ms Li claims that Mr Bray used a £50 million offshore trust set up to fund a shelter for South China tigers to hide his money. In turn, Mr Bray maintains he has committed his cash to saving endangered animals and is virtually penniless.

The couple initially fought at a hearing in the High Court in London and Ms Li complained about a ruling by judge Sir Paul Coleridge.

She argued that money put into the Save China's Tigers charity was used to fund the couple's 'personal lives' but Mr Bray disagreed.

Sir Paul ruled in Mr Bray's favour, calling her an 'unreliable' source, but Ms Li complained that there was a 'lack of detail' in Sir Paul's ruling and called for a review.

Two appeal judges last year agreed that Sir Paul's ruling should be reconsidered.

The latest hearing, at the Court of Appeal in London, heard by three appeal judges is due to end later this week.

In January, Ms Li, 53, spoke for the first time about the case in an exclusive interview with The Mail on Sunday.

She said: ‘I’m not trying to take money from charity or deprive the tigers. I am not trying to be greedy. All I want is my fair share so that I can rebuild my life. I have tried to settle this amicably but he wants me to have nothing.

Stuart Bray says he has repeatedly offered to settle out of court but claims his wife wants more money than he can give her

‘My husband is a very clever man. He didn’t even like animals that much – I had to beg him to let me have two house cats. He complained that they left hair everywhere.’

The couple, who met at business school in the US in 1990, married in 2001 and set up home in a luxury penthouse overlooking the Thames.

While her husband worked as an executive for Deutsche Bank, Li resigned from her role at Gucci to work as a conservationist, specialising in reintroducing tigers into the wild. She established the Save China’s Tigers charity, which has an 81,000-acre wildlife reserve in South Africa that is home to 20 critically endangered big cats. All are destined to be returned to their natural habitat in three reserves in China.

Mr Bray bankrolled the charity, whose celebrity supporters include martial arts star Jackie Chan, actress Michelle Yeoh and businessman David Tang, funnelling millions through a charitable trust.

But Ms Li claims she lost custody of the tigers after Mr Bray ousted her from the charity’s board in 2012. She also claims he transferred all their joint assets, including the £23 million reserve in South Africa, to the offshore trust.

She alleges that the trust is protected by a complex financial structure which makes it tax-efficient, but opaque. ‘He had all the power,’ she said. ‘I had nothing in my name except a dormant bank account. I had no idea how much he actually took home.

‘Stuart took care of our finances and I focused on the tigers.’

Ms Li, who is being represented by divorce lawyer Ayesha Vardag, added: ‘The trust became our only source of income.

‘We used it for everything, from holidays to nights out at expensive restaurants. Neither of us took a salary. It paid all our expenses.’

Mr Bray said: ‘A Family Court [in October 2014] made a finding of fact that I did not hide joint assets and also found my wife to be an unreliable witness, whose actions have been motivated by revenge.

‘I’ve repeatedly offered to settle out of court, but I can’t pay as much as she wants. It’s more than I can afford. All the money in the trust is for the tigers charity.’

Mr Bray said he no longer sat on the board of the trust and that the original sum was closer to £25 million, not £50 million.

He also insisted that he had no problems with cats, despite Li’s claims, and that she resigned from the charity of her own accord.

Judges have heard that Save China's Tigers had acquired land in South Africa with the aim of 're-wilding' south China tigers.