COPENHAGEN, Denmark (AP) — A Danish man has been arrested in South Africa on suspicion of having played a key role in a fraud case that caused a Danish government welfare agency to lose at least 111 million-kroner ($17 million), Denmark's top prosecution authority said.

Prosecutor Thomas Anderskov Riis with the Serious Economic and International Crime unit said the unidentified man was arrested Tuesday in Johannesburg as he was trying to leave the country.

Anderskov Riis said "the focus remains on arresting the main suspect" — Britta Nielsen, 64 — adding Denmark would seek the extradition of the arrested man.

His role was not known. Nielsen, a 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 her whereabouts are unknown. She is sought by the Interpol. According to Danish media, her family owns several properties in South Africa.

On Oct. 10. Denmark's minister for children and social affairs, Mai 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.

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 accounts the money was intended for.