The son of boxing legend Muhammad Ali has been detained at an airport in Washington, a day after discussing his concerns about a separate incident of airport detention with members of Congress.

Muhammad Ali Junior and his mother, Khalilah Camacho Ali, were speaking to a Democratic committee on border security on Thursday, launching a campaign in opposition to President Trump’s controversial travel ban.

The Alis were motivated to launch the “Step into the Ring” campaign after they were detained at a Florida Airport in February for almost two hours.

They later said they felt targeted because they are Muslim, and have Arabic names.

Mr Alis lawyer, Chris Mancini, said he was detained for 20 minutes as he tried to board a flight home to Florida on Friday.

Mr Ali was told by airline staff that his Illinois identification card was invalid for flying, despite using this document to travel to Washington just two days earlier.

Mr Mancini said Mr Ali spoke to Department of Homeland Security officials by telephone and showed his driver’s licence and passport before he was allowed to board.

Mr Mancini said: “This whole thing smacks of some sort of retaliation for [Mr Ali’s] testimony”.

“Going to Washington obviously opened up a can of worms at the Department of Homeland Security.”

Florida Democratic congresswoman Debbie Wasserman Schultz, who was on the same flight, tweeted: “On way home on DOMESTIC FLIGHT Muhammad Ali Jr detained AGAIN ... Religiously profiling son of ‘The Greatest’ will not make us safe.”

The Transport Security Administration has disputed Mr Mancini’s version of events, saying in a statement that it did not have the authority to detain passengers.

“Upon arriving at the airline check-in counter, a call was made to confirm Mr Ali’s identity with TSA officials,” the agency said.

“When Mr Ali arrived at the checkpoint, his large jewellery alarmed the checkpoint scanner. He received a targeted pat-down in the area of his jewelry to clear the alarm and was cleared to catch his flight.”