Contractor Wasn’t Paid By The Previous Home Owner And Is Saying They’ll Put A Lien On The Property. Options?

Hello, I am in the state of Michigan. When I purchased my home the driveway was incomplete. The contractors finished the work a few days after closing was complete. Today the contractor showed up at my front door saying the previous owner didn’t finish paying the last $1900. He gave me the old owner’s phone number and said if he or I didn’t pay he would put a lien on the property. I never paid for this contractor and they don’t even have my phone number or contact info. What are my options here?

EDIT: some more info. I had contacted my realtor about this. The sale of the house was back in July. The work finished in July shortly after closing, the work has been done since July 16th for sure. My realtor said that he reached out to the seller’s agent. He (my R) insists that we don’t owe anything and that there is clear paper trail leaving me off the hook for this.