Award-winning Azeri investigative journalist Khadija Ismayilova on Monday slammed the government's "lies" at the close of her trial on corruption charges, which opponents of strongman President Ilham Aliyev see as an attempt to muzzle independent media.

Ismayilova, who has probed the alleged vast riches amassed by Aliyev and his family, was arrested in December on charges including embezzlement and tax evasion.

Her supporters say the charges against her have been concocted by a government anxious to silence one of the few voices of independent journalism in the oil-rich former Soviet country.

Ismayilova on Monday vowed she would not be gagged, her lawyer told AFP.

In her final statement to the court, the 39-year-old journalist said prosecutors and court officials had "resorted to more and more lies and fakery," lawyer Fariz Namazly told AFP.

"All the testimony against me was received in unlawful ways, through pressure," Ismayilova accused, according to her lawyer.

"A lot of people signed their testimony without even reading it, while even some of the signatures were faked."

She vowed that even a lengthy jail sentence would not stop her from speaking out.

"They won't be able to force me to stay silent, even if they sentence me to 15 or 25 years," she said.

The judge interrupted Ismayilova mid-sentence as she began saying that she was being tried because of her investigations into high-level corruption.

"The judge cut her off, saying she was digressing," lawyer Namazly told AFP.

The judge then called a recess to begin deliberating the verdict, which is expected to be pronounced in the next few days, Namazly said.

Representatives from the embassies of Germany, the United States and Norway were present during the proceedings, but many journalists and representatives of international organisations were not granted access to the small courtroom in the capital Baku.

Namazly said he expected Ismayilova would be sentenced to seven or eight years in prison.

Rights groups accuse the government of Azerbaijan of stepping up pressure on opponents since 53-year-old Aliyev was reelected to a third term in 2013.

Earlier this month, a prominent Azeri  couple that campaigns against human rights abuses was sentenced to lengthy jail terms in a case that was also decried as politically motivated.