The US headquarters of Subway is being held to ransom by a Melbourne franchisee who has threatened to release the company's secret recipes on the internet if he is not paid $35 million.

Victoria Police are expected to be asked to investigate the threat to expose the commercial secrets of the world's most prolific fast-food chain, which generates about $18 billion in annual sales.

The alleged architect of the international blackmail plot is Arun Singhal, a 30-year-old self-described "entrepreneur" who bought the rights to a franchise in Oakleigh's town centre earlier this year.

Subway has accused Mr Singhal of creating instructional videos and a website divulging its trade secrets - known as "the System" - that would be published on the internet if he wasn't paid $35 million for his "silence".

Subway has moved to quash the threat, obtaining an emergency restraining order against Mr Singhal in the Supreme Court of Victoria last month.