A man is in Waikato Hospital after police found him with a knife blade embedded in his face.

Rural crime supervisor Detective Senior Sergeant Mike Whitehead said police were called to a Paeroa property shortly after 11pm yesterday.

"On their arrival they found a 26-year-old man with the blade of a knife imbedded in his face. The wound was just below eye level and the blade appears to have passed through the roof of his mouth.

"Though serious the injury did not appear life threatening and he was transported to Waikato Hospital by ambulance and a 20-year-old woman at the address suffered minor injuries to her neck and was taken to Thames Hospital."

Whitehead said an investigation into how the pair suffered their injuries was underway and a scene guard was placed at the property overnight.

"The property will be examined today, it appears a number of people were drinking at the address last night and two men, located at another address in the town overnight, will be interviewed by detectives today."