Speaking in the lower house of the Swiss parliament, Justice Minister Karin Keller-Sutter confirmed that one case was currently in process while several others were being considered.

The minister said that to date there had been no cases of ISIS fighters being stripped of their Swiss passport.

“But you can be certain that we will exhaust all of our powers when it comes to citizenship,” she said.

The minister went on to say that cases involving dual nationals would be given preference.

“We cannot create stateless people,” she was quoted as saying in Swiss daily Tages Anzeiger.

Under international law, it is illegal to deprive someone of citizenship it doing so leaves them stateless.

According to Swiss Federal Intelligence Service figures from November 2018, 93 jihadists had travelled from Switzerland to conflict zones since 2001. Of these, 31 have a Swiss passport and 18 are dual nationals.

Switzerland has had legal measures in place allowing for dual nationals to be stripped of their Swiss passport for a number of years.

Keller-Sutter's comments on Monday come several days after the Swiss government said that while it would not prevent Swiss citizens from returning to Switzerland from the Syrian–Iraqi conflict zone, it would not actively seek their repatriation, except in the cases of minors.

In a statement, the government said it wanted people tried in the countries where they had committed their crimes.

The comments from the Swiss justice minister also come in the wake of controversy over moves by the UK to strip 19-year-old Shamima Begum of her British citizenship. Begum left the UK aged 15 and travelled to Syria to marry an ISIS fighter.

The UK foreign affairs ministry has said Begum, who is currently in a refugee camp in Syria, is entitled to Bangladeshi citizenship through her parents but Bangladeshi authorities have disputed this.