"This litigation also involves counter claims against the joint venture partner, and in the opinion of the directors it is very unlikely that any claim against the group will be successful," it added.
Elsewhere, the company said a 10-year lease had been signed for Maze and Maze Grill Mayfair but that the former would close in January next year and be replaced by a new concept.
Kavalake also accounts for the 18 overseas restaurants that Gordon Ramsay has license agreements with.
International revenue grew by more than half to £5.4m and five more international sites are due to open in 2018, including a Hell's Kitchen concept - named after the celebrity chef's television show - which will have one site in China and four in the US.
The company said since the end of the accounting period, it had secured a five-year funding agreement with Barclays.
The company owed nearly £33m to creditors in the year following the end of the accounting period, including taxes and £12.4m of intercompany loans.