South Korean conglomerate Samsung Group reiterated that it did not pay bribes or seek illicit favours in response to the special prosecutor's announcement accusing the group's leader of paying money to curry favour from President Park Geun-hye.
"Future court proceedings will reveal the truth," Samsung said in a statement.
Among the charges against Lee are pledging bribes to a company and organisations tied to Park's confidant, Choi Soon-sil, the woman at the center of the scandal, to cement his control of the smartphones-to-biopharmaceuticals business empire.
The funding also included Samsung's sponsorship of the equestrian career of Choi's daughter, prosecutors say.
Legislation appointing the special prosecutor states that the trial should be finished in three months.
President Park, 65, daughter of a former military strongman, has had her powers suspended since her impeachment by parliament in December.
Should the Constitutional Court uphold the impeachment, she would become the country's first democratically elected president to be thrown out of office.
A decision is expected this month.