Entrepreneurial ecosystems have been explored widely in entrepreneurship, management and social sciences literature. The Knowledge Spillover Theory of Entrepreneurship (KSTE) aims to uncover the effects of information on start-ups co-located in diverse locations, such as urban areas, science and technology parks, incubators, and accelerator programs. Extant research has focused on how entrepreneurs launch start-ups and develop patents over a 5-10 years timespan from a regional perspective. However, studies into the development processes of start-ups and the creation of entrepreneurial ecosystems in physical and virtual environments in the context of high-tech start-ups, are limited. This paper aims to fill this gap by identifying the development processes undertaken by high-tech entrepreneurs at the individual level and evaluating the absorption and implementation of knowledge in physical and virtual clusters within entrepreneurial ecosystems. A multiple case study of 32 start-ups that have attended incubator and accelerator programs in London, United Kingdom, is presented. Semi-structured interviews were conducted with Chief Executive Officers (CEOs) and Founders of start-ups to propose the Model of Knowledge Spillovers and Entrepreneurial Ecosystems. The themes identified during interviews highlight the mechanisms employed by start-ups to capture tacit and explicit knowledge spillovers. Theoretically, the findings of this study contribute to the KSTE by questioning the flexibility of entrepreneurs to access knowledge without the limitation of geographical proximity to sources of knowledge. Practically, our findings provide entrepreneurs with proven mechanisms required to capture tacit knowledge spillovers within entrepreneurial ecosystems and use virtual platforms to obtain explicit knowledge spillovers towards product innovation.