The Following are RAW

"Instead of an Interrogate Test, you may instead make a Hard (-20) Inquiry Test. You never risk inflicting damage or fatique with this test"

Suggestion psychic power

"you can use this in conjuction with an Interaction Skill... You gain a +20 on Interaction Skills used this way."

House Rule.

The Psyker can use Suggestion to give another Character +20 on an interaction skill by sending the appropriate command. Ex: "tell us everything" "you want to confess" "you can trust us" could all possibly help with and Inquiry test.

Result: Gentle Interrogation.

Slight, slight veriation on Suggestion. But I like the image of the psyker applying mental pressure as the suspect is baggered with leading questions.

Should have been a topic in "House Rules", but a valid choice as far as I can see.

It allows the psyker power to be used as "support" as it is RAW (rule as written?) with most skills since the IH.