Russia today began the first full hearing in Ulyuakyev's bribery trial, the highest-profile criminal case against a top official in decades.
Ulyukayev was arrested in November while still a minister, allegedly caught red-handed taking a $2-million (1.7-million-euro) bribe in return for greenlighting state oil giant Rosneft's acquisition of a stake in another oil company Bashneft.
The 61-year-old denies the charge of massive official bribe-taking, for which he could face up to 15 years in prison.
In explosive accusations, Ulyukayev claimed he was lured to the Rosneft offices by its head Igor Sechin. It was there that a bag containing the bribe money was handed over.
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Sechin is a powerful ally of Putin, who has built up Rosneft into the world's largest publicly traded oil company.
The prosecution has asked for Sechin to be summoned as a witness at the trial.
Ulyukayev said the sting was set up on the basis of "fabricated" accusations against him, "based solely on Sechin's claims."
The former official sat in a striped blue polo shirt at a table in the packed courtroom in Moscow's Zamoskvoretsky district court.
He is being held under house arrest, not in jail, and told journalists before the hearing that he has been reading the short stories of Anton Chekhov.
Ulyukayev's arrest last year sent shock waves through Russia's liberal elite.
Investigators say he demanded a bribe from Rosneft and was caught red-handed accepting the cash, which he placed in the boot of his car. The identity of the person who allegedly paid the bribe however has not been revealed.
Putin sacked Ulyukayev as economy minister - a job he had held since 2013 - in the wake of his detention.
The next hearing will be on September 1.