A Tesla Model Y is seen in a production hall of the Tesla Gigafactory during the open day. In Grünheide, east of Berlin, the first vehicles are to roll off the production line from the end of 2021.A Tesla Model Y is seen in a production hall of the Tesla Gigafactory during the open day. In Grünheide, east of Berlin, the first vehicles are to roll off the production line from the end of 2021.

As Russia began its invasion of Ukraine, Musk and his company were praised for their assistance. His company switched on its satellite internet service, Starlink, for use in Ukraine at the request of the country's digital transformation minister, Mykhailo Fedorov. The electric car company put together Starlink equipment and Powerwalls, energy storage systems that can power that equipment, to ship to Ukraine.

There are supply chain ties to Russia. According to internal documents obtained by CNBC, Musk's electric vehicle maker has purchased millions of euros worth of aluminum from Rusal, a company founded by a Russian billionaire.

The US Treasury had sanctions against Rusal at one point, but they were lifted under President Donald Trump. The company began buying aluminum in late 2020.

Several current and former employees who spoke with CNBC on the condition of anonymity said that they fear for their jobs because of the purchase of Rusal aluminum byTesla.

The aluminum can be used to make body shells for the Model Y, as well as other things, and has been used in production on new manufacturing lines. The plant is not fully up and running yet, but recently received approval to start commercial production. Rusal aluminum has not been used in US production.

According to Interos, a global supply chain and risk management research firm, ten of the world's largest automakers buy from at least one tier-1 supplier in Russia.

Businesses were forced to ask if they can legally and morally keep paying millions of dollars to corporations that enrich the Russian federation and the Putin cronies after Moscow's aggression against Ukraine. Musk acknowledged on Sunday evening that the company is facing significant inflationary pressure in the cost of raw materials.

CNBC doesn't know how much Rusal has paid for metals. CNBC asked if the company was severing business relationships with Rusal or any other Russian companies, but they did not reply.

Rusal, the second-largest aluminum supplier in the world, was once on the US sanctions list. Rusal's parent company, EN+ Group International, appointed new directors to its board after the company's billionaire founder agreed to relinquish control.

The US Treasury Department and its Office of Foreign Assets Control were sued by Deripaska to try to reverse the sanctions that personally affected his wealth and reputation. The case was dismissed by a judge.

Rusal has not been hit with sanctions by the US since the siege on Ukraine began. The billionaire said on March 7 that the world will be different after the events in Russia.

Russian tycoon Oleg Deripaska reacts in front of the office of Gorkovsky Automobile Plant (GAZ) in Nizhny Novgorod, Russia April 16, 2019.

Rusal's controlling shareholder, EN+ Group International, is considering a transfer of the company's international assets to a new entity with no Russian owners, management or control.

Rusal didn't say anything.

Rusal is not the sole supplier of aluminum. For years,Tesla has worked with Hydro as a more significant supplier of aluminum. The company's aluminum metal production facilities are located in Europe, Canada, Australia, Brazil and Qatar.

Invoices and other documents viewed by CNBC show that Musk's car company has spent millions of Euros with Rusal. The Swiss subsidiary of Rusal has historically paid through an Austrian bank.

Records and internal correspondence show that the purchases of aluminum from Rusal began after a change of guard in the company's executive ranks and after Musk announced that the company would build a factory in Germany.

One former employee with direct knowledge said that the previous CFO, Deepak Ahuja, was allergic to doing business in or with Russia due to the rise and impacts of Russian organized crime.

After Ahuja announced his resignation in January, with Kirkhorn taking over as CFO,Tesla worked with a consulting firm to analyze the business environment and potential risks of working in Russia.

The company was aware that some of its vehicles had been imported to Russia on their own. The company has created and maintains a number of documents pertaining to the use of its cars in Russia.

By December 2020, the company decided to source some aluminum from Rusal for casting at its new plant being built in Germany.

According to Interos, which monitors global supply chains using machine learning software, ten of the world's largest automakers all have at least one direct supplier in Russia, and 27 companies based in Russia directly supply these car companies. tier 1 relationships with 13 different Russian suppliers are held by four of the largest domestic automakers.

The invasion of Ukraine by Russia is an invasion of the global supply chain by Russia according to Interos CEO and founder. We are cutting off parts of our supply chain through sanctions and war. One way companies are responding is by buying as much as they can quickly. Beyond that, they are looking for alternative sources, whether that is from another place or from another metal or material that they can use as a substitute.

The leader of the export controls and sanctions practice at the law firm of Sandler,Travis and Rosenberg spoke with CNBC about the impact of the war in Ukraine on the auto industry.

Even if it remains legal and ethically justified, it could be hard for automakers to work with Russian suppliers because of the complexity of legal compliance and the banking focused sanctions.

The US has been very thoughtful and strategic in its approach to sanctions. You have to do multiple steps of analysis on every transaction relating to Russia.

The automotive industry is concerned that it may be difficult to conduct financial transactions with Russian businesses due to the focus on banking in sanctions by Western governments.

President Joe Biden urged Congress to join the European Union in suspending normal trade relations with Russia, which would put Russia on the same tier as Cuba or North Korea.