At the final hearing in the trial of Samsung Vice Chairman Lee Jae-yong on Monday, prosecutors recommended a 12-year jail term for his alleged role in a scandal that brought down the country's last president.
Samsung Electronics investors have said their chief interest in the trial has been how long Lee will stay in detention, sidelined from fully participating in large-scale decision-making.
"We have an opportunity to establish the rule of law", special prosecutor Park Young-soo said, according to Bloomberg.
Park, who was impeached past year, and Choi are also in jail and on trial.
Lee was indicted in February on charges that including offering $38 million in bribes to four entities controlled by a friend of then-President Park Geun-hye.
The court is expected to announce its verdict on August 25.
In a wavering voice, Lee said, "I have never asked anyone, including the president, for anything for the company or my personal gain".
The 49-year-old Lee has denied all charges, arguing he did not even know who the confidante was until after Samsung executives bought horses for an agency run to benefit her equestrian daughter.
Lee and four other executives are accused of paying or promising Choi, who was handed a three-year jail term in June, more than $38m to win presidential favours and ease a controversial 2015 merger deal.
Lee became heir to the tech giant after his father and Samsung Group chairman Lee Kun-hee withdrew from business after suffering from a heart attack in 2014.
The police are investigating claims that corporate money was transferred to pay for interior decorations in the elder Lee's private home and they are expected to question company officials soon.
Despite these developments, Samsung Electronics shares have risen strongly in recent months on soaring profits, driven by strong demand for its memory chips.