US media outlet CNBC has reported that the number of Twitter's employees has shrunk by about 80 percent since Elon Musk bought the company.

CNBC reported on Friday that Twitter's full-time headcount has dwindled to approximately 1,300 active, working employees. It said the report is based on internal records of the company. The social media company had about 7,500 employees before Musk's takeover.

Twitter has been cutting its workforce in response to a decline in advertising revenue after the takeover. Many companies have stopped advertising partly because of an increase in hate speech on the platform.

CNBC also said there are fewer than 550 full-time engineers now. It cited a former engineer saying the reduced headcount will make it harder to maintain service reliability while still building new features.

Musk said the report was incorrect. He tweeted on Friday that there are about 2,300 active, working employees at Twitter. He also claimed that there are still hundreds of employees and several thousand contractors working on trust and safety of the platform.