This is an extortion attempt

What did they say to you... This number is harassing my cousin

i to got a text from this number claming i commited to sex crimes  who is this? and why are they harassing people that way

This person has been calling me over and over and i dont know who it is. He says he's a cop but i dont believe it because i have looked the number up and many people have said it's a scam and an extortion attempt.
Idk what to believe just want it to stop