Put on/on to/onto

1. I put the police on to him.

2. I put the police onto him.

3. I put the police to him.

4. Can you put me on to a cheap supermarket?

5. Can you put me onto a cheap supermarket?

6. Can you put me to a cheap supermarket?

Could you tell me the differences in meaning, what are correct English, and whether "on to" and "onto" can be used interchangeably in this case.

I think only 2 and 5 are correct English and "on to" seems to be wrong even though "put on to" is listed in some dictionaries, but "put onto" seems to be more usual and logical.