Jean-Claude Arnault, the man at the centre of a sexual abuse and financial misconduct scandal that forced the postponement of this year’s Nobel prize in literature, has been convicted of rape.

In a unanimous verdict, Stockholm district court sentenced Arnault – the husband of a member of the Swedish Academy, which awards the world’s most prestigious literary prize – to two years in prison, the minimum sentence.

The judge, Gudrun Antemar, said there was “sufficient evidence, consisting mainly of statements during the trial by the injured party and several witnesses”, to convict the defendant of one of the two counts of rape with which he had been charged.

The verdict came at the start of Nobel prize week, shortly before the award for medicine was announced.

Arnault’s lawyer, Björn Hurtig, earlier told local media his client would appeal if convicted. He has said his client strenuously denies all charges against him, describing them as a witch-hunt based on fundamentally flawed evidence.

After a trial held behind closed doors, the public prosecutor, Christina Voigt, had called for the Frenchman to be sentenced to at least three years in jail. The maximum sentence for rape in Sweden is six years.

Arnault, 72, an influential figure in Sweden’s cultural scene for many decades, faced charges of forcing a woman to engage in oral sex and intercourse in a Stockholm apartment on 5 October 2011, and of raping her again on 2 December in the same apartment while she was asleep.

In a statement, the court said Arnault, who reportedly bragged of being the academy’s “19th member”, had been found guilty on the first count and acquitted on the second. “The injured party has been awarded compensation for damages,” it added.

The scandal first erupted last November when the Dagens Nyheter newspaper published detailed allegations by 18 women accusing Arnault – who describes himself as a photographer – of rape, sexual harassment, physical abuse and harassment over a period of more than 20 years, in Sweden and France.

Eight women filed formal complaints, but all bar one of the cases were subsequently dropped for lack of evidence or because they had exceeded the statute of limitations.

The woman in the case that came to trial – a writer and academic – told police of the 2011 assaults a few days after the Dagens Nyheter report was published, saying she had not come forward earlier because Arnault was a good friend of her manager.

Bitter internal disputes over how to handle the accusations against Arnault led to the departure of seven of the academy’s 18 members, including his wife, Katarina Frostenson, a poet and playwright who stepped down in April at the same time as the organisation’s then permanent secretary, Sara Danius.

In May, the academy – which was founded by King Gustav III in 1786 and is still under royal patronage – announced that in view of its “currently diminished” membership and the public’s “reduced confidence” in its deliberations, it would not be awarding a prize this year. Two laureates are to be announced in 2019.

For many years, Arnault and Frostenson ran Forum, a club in Stockholm that showcased exhibitions and readings by prominent cultural personalities including Nobel laureates. The club was partly funded by the academy, prompting secondary allegations of a conflict of interest.

As the scandal unfolded, Dagens Nyheter also reported that an internal investigation by the academy had concluded Arnault may have leaked the names of seven Nobel literature laureates – the subject of heavy betting – in advance of their announcement, including those of Bob Dylan in 2016 and Harold Pinter in 2005.