The appearance by Prince Alwaleed bin Talal, a nephew of Saudi Arabia's King Abdullah, was a rare instance of a senior Saudi royal being subjected to a hostile public grilling.
The prince is being sued by Daad Sharab, a Jordanian businesswoman who says she was not paid a promised 10 million dollars commission for brokering the sale of the jet to Gaddafi, which was completed in 2006 for 120 million dollars after years of delays.
At number 26 on the Forbes global ranking of billionaires, Prince Alwaleed is worth 20 billion dollars according to the US magazine and closer to 30 billion dollars by his own estimate.
At one point when asked in court about a 500,000 dollars commission he had paid Sharab for a previous Libyan deal, it was suggested to him that this was a small amount relative to his fortune.
"Each dollar counts for me," the prince responded.
He told the court he had asked Sharab to "open the door" to Gaddafi over the jet sale but had never agreed a figure for her commission. He said he did not pay her anything in the end since in the course of the sale, she had "moved to the Libyan camp".
The prince was addressed as "Your Highness" by his lawyer and by Judge Peter Smith, but his royal status did not shield him from the robust questioning style of Sharab's lawyer, Clive Freedman, who accused him of minimising Sharab's role, contradicting himself and evading questions.
"Would you please answer my question? I have asked it twice and I will ask it again," Freedman told the prince at one point.
The Airbus A340 at the centre of the dispute was used by Gaddafi in 2009 to pick up Lockerbie bomber Abdel Basset al-Megrahi when he was freed from a Scottish jail.
In 2011, it became a trophy for rebels who toppled Gaddafi and were photographed on its silver-coloured leather sofas.
The prince said the jet, which boasted a king-size bed and a meeting room with a throne-like leather armchair, was only one item on a huge business agenda he had with the Libyan leader.
"I used to call him personally by the way," he told the court, saying that in the era when Gaddafi sought international rehabilitation, he had seen Prince Alwaleed as someone who could help him bridge the gap between the Arab world and the West.
The prince said the sale of the Airbus had run into trouble because after the Libyans had paid him an initial 70 million dollars in 2003, Ahmad Qadhaf Al-Dam, a cousin of Gaddafi, demanded a bribe before arranging the payment of the remaining 50 million dollars.
The prince refused to pay and kept the plane in Riyadh, leading to several years of deadlock until he personally resolved the issue with Gaddafi in 2006, he said.
He said Sharab had played no part in the final deal and that any gratitude he may have felt for her earlier role had gone since she had "stabbed him in the back" to work for the Libyans.
He also denied proposing marriage to Sharab during the process, as she alleged in her evidence last week.
"I can only assume that (Sharab) is seeking to gain some advantage in the proceedings by attempting to embarrass me," he said in his written witness statement.