The judge in the trial of former Yukos chief Mikhail Khodorkovsky is expected to give her verdict on Wednesday.
Prosecutors want Mr Khodorkovsky to get 10 years in jail if found guilty
Mr Khodorkovsky is accused of multiple charges of fraud and tax evasion, and if found guilty could be jailed for up to 10 years.
He has always protested his innocence, and many commentators argue that his trial is politically motivated.
Analysts say he is being punished by the Kremlin for his political ambition.
Associated press says he has been charged on seven articles of the criminal code.
The charges include: theft of someone else's property by fraud, causing property damage by fraud, tax evasion and insurance theft involving large amounts, embezzlement and forgery of official documents.
Before his arrest and imprisonment in 2003, Mr Khodorkovsky had started to fund opposition political parties.
Russian authorities have all but brought former oil giant Yukos to its knees during Mr Khodorkovsky's time behind bars.
Moscow demanded $27.5bn (£15bn) in back-taxes and in December 2004 forced the sell off of its former major oil producing unit Yuganskneftegas (Yugansk) to help pay the bill.
"All this is being done for self-serving reasons," said Mr Khodorkovsky in his closing statement to the court.
"They [Russian authorities] have put me in jail so I can't stop them looting Yukos."
Platon Lebedev is also in custody
The charges against Mr Khodorkovsky relate to the privatisation of Apatit, a fertiliser firm, in the 1990s.
He is standing trial alongside former colleague Platon Lebedev, who also protests his innocence. The trial has taken 10 months.
Russian state oil firm Rosneft was the eventual purchaser of Yugansk, which it bought for $9.4bn.
However, Andrei Illarionov, a Kremlin econonomic aide who speaks his mind, said Mr Putin's Monday state-of-the-nation speech could contain hints that jail was not the only route.
"By maintaining the independence of the court from the executive authorities, a correct and fair ruling may be handed down, freeing the two citizens being investigated from tax terrorism," Mr Illarionov was quoted by the Interfax news agency as saying.
But others think Mr Khodorkovsky will be kept in jail till after the presidential elections in 2008.
Separately, there were signs Yukos' former oil-producing unit Yuganskneftegas and one of Yukos' most prized assets, could remain as part of Rosneft. Russia's economic development and trade minister said on Tuesday, Yugansk could be kept by state-run Rosneft, Associated Press reported.
This could affect or even derail a planned merger between Rosneft and Gazprom, which could have seen Gazprom control Rosneft, and the State increase its stake in Gazprom from 38% to 51%.
However, it is not yet clear what the outcome of this proposed merger will be and there have been conflicting statements about it this year.