Elon Musk and an ex-Twitter official argued over "free lunches" at the company's headquarters after a report emerged that under the new CEO, the company would stop picking up the tab for the daily meal.

In response to a tweet of a New York Times article that said Musk "plans to begin making employees pay for lunch – which had been free – at the company cafeteria," Musk claimed that despite Twitter staff not coming to the office over the past year, the cost of each lunch served was upward of $400.

After Musk's comment, ex-Twitter executive Tracy Hawkins, who ran the meal program at the firm, joined the discussion and accused him of lying.

"For breakfast and lunch, we spent $20-$25 a day per person. This enabled employees to work thru (through) lunchtime & mtgs (meetings). Attendance was anything from 20 to 50% in the offices," said Hawkins, who mentioned that she resigned a week ago as she did not want to work for the new Twitter CEO.

Musk dismissed Hawkins' claims as "false" and said Twitter spends $13 million annually on food services for the headquarters.

"Badge in records show peak occupancy was 25%, average occupancy below 10%. There are more people preparing breakfast than eating breakfast. They don't even bother serving dinner, because there is no one in the building," he added.