Cape Town radio man Zane Ibrahim was taken off an international flight minutes after it landed at Baltimore airport by United States Homeland Security personnel and interrogated for almost 12 hours.

Ibrahim, an award-winning journalist and managing director of Bush Radio, had flown to the US from Cape Town via Amsterdam to deliver a keynote address on 10 years of South African democracy at a conference at Goucher College, near Baltimore.

Ibrahim said on Friday by telephone from the US that his aircraft was still on the runway when guards boarded the flight, removed him, strip-searched him and interrogated him in the airport building for nearly 12 hours on Thursday.

Reached at his hotel, just after his encounter with the almost a dozen security officials, an angry Ibrahim said he was shocked and disturbed.

He said the first thing he knew was an announcement on the aircraft. "They said, 'Will everyone just remain seated, security agents are coming aboard.' Then four uniformed and four plainclothes officers boarded the plane. Four passed and positioned themselves behind my seat and four came up towards me and asked if I was Zane Ibrahim."

Ibrahim said he was "bumrushed" off the plane, in full view of hundreds of other passengers, bundled into a van, driven to a remote location and strip-searched by several officers. "They went through all my bags, put me through this humiliating search and then put a thick dossier on the table. Then the questions started."

Ibrahim went on to say that he was interrogated for almost 12 hours about his work as a journalist.

"I don't know what was wrong with these people, but they seemed really angry about an anti-war campaign we had running on Bush Radio, called Bush Against War."

Ibrahim said that when he did not appear at the airport, colleagues who were there to meet him made inquiries and eventually he was released, without an apology.

"They simply told me that I could go about my business, but I should remember that they were keeping a very close eye on me."

He was scheduled to deliver his address on Friday, and returns to South Africa at the weekend.