In a writ of summons issued on June 13 to Hong Kong's High Court, Alireza claims that Elman as well as a company called Fleet Overseas (New Zealand), which is allegedly affiliated with Elman, failed to pay out shares of Noble Group following Alireza's departure of the company in 2016.

The writ, seen by Reuters, demands the payment of the outstanding shares and, "in addition, the Plaintiff (Alireza) claims damages for late delivery (of the shares), based on the difference in value of the shares when they ought to have been delivered on February 1 2015 ... and the date of actual delivery."

The document claims Alireza is owed two batches of shares totaling 1.4 percent of Noble Group's stock, which it claims have a combined value of S$79.2 million (45 million pounds).

The document also demands "damages for late delivery."

Noble had no comment. Elman did not immediately respond to an email seeking comment.

A writ of summons is used to start legal proceedings and can lead to legal action if the demands are not met.

The shares of Hong Kong-based but Singapore-listed Noble Group have collapsed by 98 percent from their 2011 peak to just 32 Singapore cents as the company battles accusations of murky accounting and a broad commodity downturn.

The firm's market capitalization has slumped from a peak of more than S$10 billion to just S$430 million.

The company is in negotiations with banks over a roll-over of a $2 billion credit facility, and it is also being sounded out by rival trading houses for its remaining business, which is mainly focused on thermal coal trading but also includes U.S. oil assets.

The court document states that Alireza approached Elman in early May of 2016 and "raised his concerns over the future viability of the Noble Group."

Alireza left the company later that month.

(Additional reporting by Anshuman Daga and Aradhana Aravindan; Editing by Richard Pullin)

By Henning Gloystein and Masayuki Kitano