A Danish woman considered the main suspect in a fraud case that caused a Danish government welfare agency to lose at least 111 million kroner ($17 million) has been arrested in South Africa.

Denmark's top prosecution authority said Anna Britta Troelsgaard Nielsen was arrested Monday in Johannesburg, and Denmark will seek her extradition.

Prosecutor Thomas Anderskov Riis added her arrest was the result of cooperation between Denmark's Serious Economic and International Crime unit and a series of international authorities that he didn't name.

"We have asked South African authorities for her extradition to Denmark. We believe the chances are good," police investigator Thomas Anderskov Riis said.

Nielsen's Danish attorney, Nima Nabipour, told public broadcaster DR she wanted to "return as soon as possible to Denmark so that she can take part in the investigation."

The minister for children and social affairs, Mai Mercado, welcomed the arrest as did Justice Minister Soren Pape Poulsen.

On Thursday, a man suspected in the same case also was arrested in South Africa with suspicions of handling stolen property. His extradition has also been requested.

Nielsen, a 64-year-old civil servant for 40 years with the National Board of Health and Welfare, is suspected of stealing money intended to help vulnerable people, including the homeless and disabled.

Shortly before the fraud was made public last month, Nielsen vanished from Denmark and was sought via Interpol. According to Danish media, her family owns several properties in South Africa.

On Oct. 10., Mercado said Nielsen, whom she described as "a trusted employee," had "abused" her position to commit systematic fraud from 2002 to 2018.

It was not clear how Nielsen stole the money, but it appears she had privileged access to the agency's computer system. The scam was detected at the end of September during an audit.

A preliminary probe by the Ministry for Children and Social Affairs says that at least 274 money transfers were made during the period to accounts in Nielsen's name, instead of to the intended accounts.