Senior Public Prosecutor Leif Gorts confirmed that the investigation had been launched following reports of potential corruption between 2011 and 2019.

"We have reason to believe that crimes of corruption may have been committed in Iraq during this time period and therefore deemed it necessary to open a preliminary investigation," Gorts told AFP, stressing it was still in its "early stages."

The network equipment maker's chief executive Borje Ekholm conceded in a newspaper interview in February that some Ericsson employees may have bribed IS members for road transport through areas controlled by the group in Iraq.

The admission was made before the publication of a report by the International Consortium of Investigative Journalists (ICIJ) revealing that an internal Ericsson investigation from 2019 was never made public.

The internal probe had identified possible corruption between 2011 and 2019 in the group's Iraqi operations.

Ericsson has already agreed to pay $1 billion in penalties to US authorities to close corruption cases in Djibouti, China, Vietnam, Indonesia and Kuwait in 2019, and said last week that it expected it would have to pay more fines over the Iraq case.

At Ericsson's annual meeting in late March, shareholders voted against discharging Ekholm and the board from liabilities, a normally routine decision.

Both Ekholm and board members were nonetheless re-elected to their positions.

The Swedish firm's shares have lost over a quarter of their value since mid-February.