Twitter is considering legal action against Meta over its fast-growing rival app Threads.

Threads, which was launched to millions on Wednesday, is similar to Twitter and has been pitched by Meta bosses as a “friendly” alternative.

Twitter’s Elon Musk said “competition is fine, cheating is not” – but Meta denied claims in a legal letter that ex-Twitter staff helped create Threads.

More than 30 million people have signed up for the new app, according to Meta.

The look and feel of Threads are similar to those of Twitter, BBC News technology reporter James Clayton noted. He said the news feed and the reposting were “incredibly familiar”.

In a move first reported by news outlet Semafor, Twitter attorney Alex Spiro sent a letter to Meta CEO Mark Zuckerberg on Wednesday accusing Meta of “systematic, wilful, and unlawful misappropriation of Twitter’s trade secrets and other intellectual property” to create Threads.

Specifically, Mr Spiro alleged that Meta had hired dozens of former Twitter employees who “had and continue to have access to Twitter’s trade secrets and other h