The staffer died on Monday and the nine colleagues who have tested positive were from a team of 30 which used to spend a fortnight at the commodity bourse's office in suburban Andheri by rotation since the lockdown was announced in March, the officials said.
However, it was still unclear if the office has been sealed and if so, how is the exchange continuing with its operations.
A query sent to MCX remained unanswered.
The financial capital has turned into a hotspot of the coronavirus infection, accounting for nearly a fifth of the over 2 lakh positive cases in the country so far.
Financial institutions, especially systemically important ones like exchanges and regulators, have core teams to ensure operational continuity.
In the case of MCX, there were two teams of 30 people each mandated with ensuring business continuity out of the city office. They used to work from the office for two weeks by rotation, officials said.
The deceased staffer's samples tested positive on Friday, leading the bourse to start testing all the employees he was in close contact with. Tests on the other employees led to the discovery of nine more who have been infected with the virus, officials said.
They said the deceased staffer was during a break away from his work roster when he died and the exact details of when he got infected were not immediately known.
An official said necessary precautions like sanitising the facility have been undertaken by MCX. AA ABM ABM