A fund backed by South Africa"s richest woman has emerged as the biggest shareholder in Oxford University"s £600m spin-out arm, which has been rocked by a boardroom rift over strategy. The Telegraph understands that Braavos Capital, an investment vehicle whose partners include billionaire Magda Wierzycka, has built up around a 20pc stake in Oxford Sciences Innovation (OSI) during the past six months, buying shares from Neil Woodford"s fund, IP Group and Invesco. Mr Woodford sold out of the incubator last May, following a string of problems at his fund. OSI was established in 2013 as a university venture fund to invest in some of Oxford University"s most promising spin-out companies. Other shareholders include Google Ventures, Tencent and Huawei, the Chinese telecoms giant. Details of the shareholding have emerged just days after Patrick Pichette, the former Google chief financial officer, stepped down as chairman of OSI, following the exit of Charles Conn, the former chief executive who left in November. Both men had joined less than a year ago. Andre Crawford-Brunt, another of Braavos Capital"s partners, is thought to have driven the investment in OSI, and will take up a board seat. Sources said a "misalignment in views" over the direction to take for the fund was behind the departures, with investors including Mr Crawford-Brunt pushing for Mr Conn to leave. Mr Conn declined to comment. In a statement earlier this week, OSI said Mr Pichette had quit to focus on other international commitments. As well as OSI, he helped launch the Creative Destruction Lab mentorship programme in Oxford, and holds a board seat at Twitter. He is thought to have also been trying to push through reform. He said: "I wish to thank management and the Board for the opportunity to serve OSI for the last year and look forward to the company’s next phase of growth.” Jim Wilkinson, interim chief executive at OSI, said: "Over the last four years, OSI has transformed the ecosystem in Oxford, increasing by fourfold the number of university spin-out companies and attracting significant global investment and talent to the UK tech industry. “While the last few months have seen changes to our board and executive team, our strategy has always remained the same – to identify and develop cutting edge science and technology from the University and create and grow world-leading companies. “This is the team’s sole focus – and it is fully backed by our board and investors.”