The former chief prosecutor of the International Criminal Court has urged for countries to issue an international arrest warrant for Vladimir Putin as he is “war criminal.”

In an interview with Swiss newspaper Le Temps, Carla Del Ponte said: “Putin is a war criminal,” which was published on Saturday.

The Swiss lawyer who oversaw the United Nations investigations in Rwanda and the former Yugoslavia said it is clear that war crimes are happening in Ukraine.

Read more on Russia-Ukraine war:

‘Butcher’ Putin is ‘really upset’ at being ‘misinformed’ by his own Generals which ‘is messing with his head’

Putin warned there are ‘classic signs of an impending coup’ as ‘dissension has broken out at the highest levels in government’

Russian soldiers ‘torture’ innocent civilians and leave their ‘dead bodies riddled with bullets’ in the streets

‘Hitler’ Putin commits ‘one of the worst crimes of the war’ by blowing up a Red Cross building in Mariupol

She was shocked by the use of mass graves in Ukraine, which have been seen in areas such as Mariupol and elsewhere in the country.

She told the newspaper Blick, “I hoped never to see mass graves again.

“These dead people have loved ones who don’t even know what’s become of them.

“That is unacceptable.”

She said an investigation against Putin and his forces will be much easier than Yugoslavia because the Ukraine has already requested an international investigation into war crimes being committed by Russian forces.

The current International Criminal Court chief prosecutor, Karim Khan, visited Ukraine last month, and should she find any proof of war crimes, “you must go up the chain of command until you reach those who took the decisions,” Del Ponte said.

She said it would be possible to bring Putin to account, “You mustn’t let go, continue to investigation.

“When the investigation into Slobodan Milosevic began, he was still president of Serbia.

“Who would have thought then that he would one day be judged?

“Nobody,” she told Blick.

Del Ponte added that an investigation into war crimes will be carried out which will look at the Ukraine as well as Russian troops, and Russian prisoner of war being held.