It has been revealed that $200.6 million of the revenue which Tesla posted last quarter came from non-ZEV credit sales, Auto News reports.

In an April 24 letter to shareholders, Tesla chief executive Elon Musk noted that Tesla sold $15.4 million in zero-emission vehicle regulatory credits in the first quarter of the year. What Musk failed to mention was the $200.6 million in non-ZEV credit sales which it also made during the first quarter.

Tesla only disclosed these credit sales in its 10-Q filing released on Monday.

“We are disappointed at Tesla’s decision to not report or discuss non-ZEV credits explicitly on last week’s earnings call, given their material impact on this quarter’s automotive gross margins.” Wall Street analyst from Bernstein, Toni Sacconaghi said.

Tesla’s 10-Q failing doesn’t specify where the company’s non-ZEV regulatory credit sales are coming from but Sacconaghi has noted that they do include federal greenhouse gas credit sales. The $200.6 million in sales played a key role in boosting the car manufacturer’s first-quarter revenue from $988.5 million twelve months ago up to $3.72 billion.

Laws in California require car manufacturers to sell electric and non-polluting vehicles in proportion to their respective market share. If they’re unable to do this, they have to purchase credits from companies such as Tesla.

When disclosing its gross margin figures to investors last week, Tesla published a figure of 20.3 per cent. However, Sacconaghi suggests the car manufacturer’s gross margin would have been 16.1 per cent if it wasn’t for the credit sales.

Carscoops has contacted Tesla seeking additional information about its non-ZEV regulatory credit sales.