PALO ALTO, RAW – Tesla has added “Technoking of Tesla” to billionaire chief executive Elon Musk’s list of official titles, in a regulatory filing that also named finance chief Zachary Kirkhorn “Master of Coin”.

The electric car maker did not explain the reasons for the cryptic new titles on Monday. Last month, Tesla revealed it had purchased $US1.5 billion ($A1.9 billion) of bitcoin and would soon accept it as a form of payment for cars, sending the price of the world’s most popular cryptocurrency soaring.

Later on Monday, Musk tweeted an animation depicting what appeared to be a golden trophy decorated with coins and accompanied by a pulsing electronic soundtrack.

“I’m selling this song about NFTs as an NFT,” the tweet said.

Non-fungible tokens, or NFTs, are a new type of digital asset that is authenticated by blockchain, which certifies its originality and ownership.

Their popularity has exploded during the pandemic, as enthusiasts and investors scramble to spend enormous sums of money on items that only exist online.

The buyer of a $US70 million digital-only artwork was named last week by auction house Christie’s as a crypto asset investor who goes by the pseudonym “Metakovan”.

Musk’s recent promotion of dogecoin on Twitter has also lifted the price of that cryptocurrency.

Bitcoin hit new highs of near $US62,000 at the weekend but retreated about five per cent early in the European day on Monday.