Tesla has not responded to a request for comment when contacted by CNBC.

The document was first uncovered by data platform CB Insights on Monday. Straubel and Stevenson are named as executive officers and directors of this company. Stevenson is also down as chief financial officer. When CNBC tried calling the number on the SEC form linked to Redwood Materials, it went to the voicemail box of Stevenson.

Jeffrey Straubel, chief technical officer, and Andrew Stevenson, head of special projects at the auto firm, were on a U.S. Securities and Exchange Commission (SEC) filing highlighting a $2 million fundraiser for the Redwood Materials.

Two Tesla executives have been named as directors of a company called Redwood Materials, which appears to focus on technology to recycle and reuse manufacturing materials.

Redwood Materials describes itself as making "advanced technology and process development for materials recycling, remanufacturing, and reuse", on its website.

The SEC filing shows that the company was set up in 2017 and is based in Redwood City, California. It has raised $2 million from just one investor but the name of the backer is not disclosed.

Stevenson signed the document on April 28 after the equity was sold on April 17.

The extent of Tesla's involvement with Redwood Materials is unclear, but if it were a partner, customer or even investor, it would certainly make sense. The company, which is run by billionaire Elon Musk, has been focused on ways to make its supply chain more efficient in order to scale and meet demand.

Tesla opened the Gigafactory earlier this year which is producing battery cells for the company's energy storage products. At the same time, Tesla is said to be ramping up production for its Model 3 car, a vehicle that is aimed at the mainstream.

Last year, Tesla also acquired SolarCity as it continues to push its ambitions in the clean energy space.

Using a company like Redwood Materials would allow Tesla to own more of the supply chain, potentially helping to boost production, and in a more sustainable way, given that it would be recycling materials to be manufactured into different parts.

U.S. technology companies have been looking for ways to make their supply chain more responsible. Last month, Apple pledged to end its "reliance" on mining and one day make its products from only renewable resources or recycled material.