SAN JOSE: Facebook founder Mark Zuckerberg's enthusiasm for martial arts has forced the Meta Group, which he heads, to issue an unusual warning to investors.

Zuckerberg and several other managers took part in "various high-risk activities, such as combat sports, extreme sports, and recreational aviation" which run the risk of "serious injury and death", Meta stated in a detailed report to the Securities and Exchange Commission (SEC) over the past year, which was published over the weekend.

It is the first time that the Facebook group has included such a reference to the head's hobbies in the usual risk warnings for investors.

As before, Meta also emphasised that if Zuckerberg were no longer available for whatever reason, this could have a "material adverse impact on our operations."

Zuckerberg has a controlling stake in Meta thanks to shares with more voting rights than ordinary investors - and continues to play a leading role in determining the group's strategy.

Meta has billions of users on its platforms, which include Facebook, Instagram and WhatsApp.

 - dpa