Ingela Jansson, one of the Sweden's most notorious fraudsters, was arrested in Ethiopia in January 2010, having absconded from Sweden in 2007.
In mid-May, an Ethiopian court handed Jansson a 25-year prison sentence, convicting her of 20 counts of fraud and human trafficking.
A 35-year-old Swedish accomplice was also convicted and sentenced to 23 years in prison.
"Both have appealed some of the points on which they were convicted. The embassy is there following the case and visiting the Swedes in prison," foreign ministry spokesperson Karin Nylund told the Aftonbladet newspaper.
The 30-year-old from western Sweden is well known in police circles in Sweden.
Her criminal activities first came to light in 2003 when she was charged with fraud after leasing cars in her boyfriend's name, then selling them on the black market.
In a bid to receive a reduced sentence during her trial in Sweden, Jansson testified against the so-called Naser league, and was provided with police protection and a new identity.
However further criminal activities came to light in the ensuing years and she was eventually arrested once again in 2006. This time she was accused of fraud amounting to millions of kronor related to several incidents of deception involving cars, hotels and cash.
The case came to court in 2007 but the day before sentencing, Jansson absconded and was sentenced to two and a half years in jail in her absence.
She was re-arrested in Ethiopia last year and her trial started last summer.
Swedish prosecutors are still working to have Jansson extradited to Sweden, but according to prosecutor Jakob Holmberg told Aftonbaldet that Ethiopian authorities are waiting to process the request until after legal proceedings in Ethiopia are completed.