Co-founder used company funds for personal expenses without informing me?

I'm from Bengaluru and my co-founder has been using our startup's funds for personal expenses like holidays and shopping. We had a verbal agreement to only spend on business-related costs. I've just discovered this by checking the accounts, and he didn't inform me at all. I'm worried about the implications for our business finances. We haven't signed any operating agreement yet. What legal action can I take to ensure our business isn't jeopardized and hold him accountable?