He told me he was a fraud investigator from IRS and said i was suspected of money laundering and i owed a fine of $1850

Laugh at him & tell him his SCAM is pathetic.  The IRS mails letters if there is a problem .

The IRS reminds people that they can know pretty easily when a supposed IRS caller is a fake. Here are five things the scammers often do but the IRS will not do. Any one of these five things is a tell-tale sign of a scam. The IRS will never:
Call to demand immediate payment, nor will we call about taxes owed without first having mailed you a bill..

Demand that you pay taxes without giving you the opportunity to question or appeal the amount they say you owe.

Require you to use a specific payment method for your taxes, such as a prepaid debit card.

Ask for credit or debit card numbers over the phone.

Threaten to bring in local police or other law-enforcement groups to have you arrested for not paying.