The 44-year-old son of late boxer Muhammad Al is 'stepping into the ring' against President Donald Trump with a religious freedom campaign.

Using the hashtag #AlivsTrump, Muhammad Ali Jr and his mother Khalilah Camacho Ali are launching the campaign after he was detained at Fort Lauderdale-Hollywood International Airport when returning from Jamaica.

Salon reported last month that Ali was challenged returning from a Black History Month event when he was challenged by a border agent with the question: 'Where did you get your name from?' He was separated from his mother and detained for two hours.

'Immigration came up to me and pulled me aside and asked me my name first and I said "Muhammad Ali". And he said, "What religion are you?" And I said, "Muslim".'

He was then subjected to questioning, even though Jamaica was never one of the seven 'travel ban' countries, the travel ban was on hold, he was born in Philadelphia and uses a US passport.

Camacho Ali said: 'There shouldn't be a travel ban. If I don't speak up now, they're going to keep harassing us.'

Ali and his mother believe they were targeted because of their religion.

'We, as a family, have been fighting this for a very long time. We are going to continue to fight for religious justice,' his mother told Associated Press.

The late boxing champion Muhammad Ali was a lifelong civil rights campaigner who converted to Islam.

The campaign quickly began to trend on Twitter: