As part of the financial injection, Paul Harris will join the operator’s board and bring a "wealth of experience" in travel and corporate finance.
The Harris Family sold its majority stake in Butlin’s, Warner Leisure Hotels and Haven parent company Bourne Leisure last year.
The Adventure People is in the process of doubling the size of its technology team as well as hiring for roles in sales, marketing and commercial.
Chief executive Chris Roche said the company has found the past two years "incredibly challenging".
"With our heads down, we focused on our technology and customer offering," he added. "Despite the difficult market conditions, the business continued to grow throughout the pandemic.
"We have now been fortunate to secure significant backing which will allow us to pursue our goal of being the global market leader for adventure and experience based holidays."
