(CNN) -- The son of former Chinese Communist leader Bo Xilai told CNN on Tuesday that he has submitted a witness statement to the defense team for his mother, who will stand trial this week in the death of a British businessman.
"As I was cited as a motivating factor for the crimes accused of my mother, I have already submitted my witness statement," he wrote in an e-mail. "I hope that my mother will have the opportunity to review them."
Bo Guagua did not specify what he wrote in the witness statement.
Authorities have said that Bo Guagua and his mother, Gu Kailai, had disputes with Neil Heywood over "economic interests." They also claim that Gu and accomplice Zhang Xiaojun poisoned Heywood in November out of concern that he posed a threat to the younger Bo's personal security.
"I have faith that facts will speak for themselves," Bo Guagua said of the trial, which is scheduled to take place on Thursday.
If convicted, Gu could face the death penalty, but a friend of her family has told CNN her life is expected to be spared if she is convicted.
Bo Guagua, 24, graduated from Harvard's Kennedy School of Government in May. He previously attended Oxford, graduating in 2010.
He came under fierce scrutiny this spring as bare-chested photos of him at college balls led to accusations of a party-boy lifestyle, fueling a long-raging debate in China about whether Chinese Communist Party leaders exploit their positions to enrich their families.
In a letter to the Harvard Crimson in April, Bo Guagua denied he had ever driven a Ferrari to pick up a date and defended his academic record.
"I am deeply concerned about the events surrounding my family," he said at the time, adding that he had no comment on the investigation.
Media reports have suggested that Heywood was at one time a mentor to Bo Guagua, paving his entry into England's elite Harrow School, from which he graduated.
Heywood was found dead in his hotel room in the southwestern Chinese metropolis of Chongqing, and authorities quickly blamed his death on excessive alcohol. His body was cremated without an autopsy.
On April 10, authorities made the surprise announcement that Gu was being investigated on suspicion of murder, along with Zhang, a family aide.
Bo Guagua's father, Bo Xilai, was seen to be a top contender for China's powerful Politburo Standing Committee before his career unraveled this spring after Heywood's death.
That same day in April, Bo Xilai was stripped of his seat on the Communist Party's Central Committee for an unspecified "serious breach of regulations."
CNN's Jaime FlorCruz and Steven Jiang contributed to this report.