What should my friend do after submitting a fake certificate?

Hi, one of my friends submitted a parent’s birth certificate for passport verification, but during the verification, the certificate was found to be fake. He applied for the passport in Mumbai, but his parents are from Uttar Pradesh. He contacted an agent in Uttar Pradesh, who took ₹1000 and created a fake birth certificate for his parents. He submitted this certificate to the police, but it was later found to be fake. The police called him and asked him to go to Uttar Pradesh, file a complaint against the agent, and submit a copy to the Mumbai police. He went to Uttar Pradesh, obtained the genuine birth certificate from the district, and sent it to Mumbai police, who verified the certificate as genuine. Now, the police are asking him to file a complaint against the agent who provided the fake certificate. What should he do now? Is he in any danger? Please help.