If you invested in the proprietary token offered by the now-defunct crypto exchange BitConnect, the FBI wants to hear from you.

In a notice on its website Wednesday, the federal law enforcement agency said those who invested in the BitConnect coin (BCC) token can voluntarily reach out to the agency by filling out a questionnaire.

The FBI said investors’ responses would be “useful” as it investigates the case, and that it may reach out to respondents for additional information.

BitConnect closed down its crypto-lending platform in January 2018 following the issuance of cease-and-desist orders from Texas and North Carolina securities regulators, which claimed the company was engaging in an unregistered securities sale through its initial coin offering (ICO).

As a result, BitConnect’s BCC token plunged more than 90 percent, falling from over $400 to less than $20 in the first weeks of 2018. Crypto market data site CoinMarketCap now no longer lists the token.

The sudden loss in value led to several lawsuits seeking restitution for investors who saw their holdings become almost worthless, citing fraud and securities sale laws.

The FBI said in Wednesday’s statement:

“Bitconnect guaranteed investors up to a 10 percent total return per month on their investment, following a tiered-investment system based on the sum of an investor’s initial deposit.”

Back in March 2018, Trevon James, former BitConnect investor and promoter, said that the FBI was investigating the case and that he had spoken to the agency about the exchange and his involvement with the project.

“I’m glad that I don’t know anything, so that means there’s no proof that I knew anything,” James commented at the time.

In August 2018, the Criminal Investigation Department of the Indian state of Gujarat police arrested former BitConnect India head Divyesh Darji after receiving an alert from the country’s immigration agency.

The BitConnect case is now running as a single legal effort in the U.S. In October 2018, an Amended Consolidated Class Action Complaint was initiated in the U.S. District Court for the Southern District of Florida that also named additional BitConnect owners and promoters who were previously not part of any lawsuits.

FBI agent image via Shutterstock