Authorities say a psychological examination has shown that a man who stabbed a candidate to be Cologne mayor can be held criminally responsible for his actions.

The 44-year-old German on Saturday stabbed Henriette Reker, a leading candidate in Sunday's election for new mayor of Cologne. Reker is currently responsible for housing refugees in the city and officials have said the man told them he acted out of anti-foreigner motives.

Prosecutors and police said they will seek to keep the man, who has not been named, in custody on suspicion of attempted murder and dangerous bodily harm.

They said the suspect has told them that he was actively involved in the right-wing scene in the past.