(Bloomberg) -- On a September morning in 2015, between 20 and 30 police officers surrounded the London apartment of day trader Walid Choucair, banged on the door and arrested him in an insider trading probe, a jury heard on Tuesday. He says he wasn’t the real target of the investigation.

Officers from the National Crime Agency searched the apartments of Choucair and his mother in London’s exclusive Knightsbridge neighborhood, two or three weeks after she’d had a heart attack, he told the court. He said he refused to answer questions from the police because he was upset that officers were stressing his mother despite her medical condition. She’d also had cancer in 2007 and was a diabetic, he said.

"I was angry," Choucair said, raising his voice in the London courtroom. “My phones are being tapped and someone knows that this woman has had a heart attack. She was my only relative in the world. Why on earth would you go and raid her house at 6.30 in the morning, restrict her to her kitchen, saying you’re looking for suitcases full of cash?”

Choucair, 39, and his friend, former UBS Group AG compliance officer Fabiana Abdel-Malek, 36, are on trial for five counts of insider trading. The Financial Conduct Authority accuses Abdel-Malek of leaking price sensitive information from the bank’s deals database to her friend using burner phones, allowing him to trade on the information and land 1.4 million pounds ($1.8 million) in profits. Both deny the accusations.

Emotions

Choucair raised his voice in court and started gesticulating as he recounted the events, including how he learned that he stumbled into the investigation and wasn’t the target. In July 2014, Choucair met his friend and fellow day trader Alshair Fiyaz at the Four Seasons Hotel on London’s Park Lane to discuss some trades they were planning, he told the court.

Unbeknownst to Choucair at the time, the conversation was recorded. Later that summer, Fiyaz told Choucair of the investigation, and then Choucair discovered that the authorities were listening to his phones, he said.

Choucair said he didn’t answer questions in his police interview because of his doubts about the case.

“I didn’t trust them,” Choucair said. “I knew the investigation wasn’t about me. It was never about me.”

As he spoke faster and became more animated, the judge broke him off.

"Sorry, your honor," Choucair responded. "I’m just getting a little emotional here."

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