The case involves alleged money laundering and tequila and authorities think it has El Chapo's fingerprints all over it.
The soap opera actress acted as the middle man between Sean and El Chapo after the drug lord had escaped from prison. She was with Sean as he secretly chatted with Chapo for his highly controversial Rolling Stone article.
Reports have since come out where Kate alleged that she didn't know the meeting was for a news story.
That could be the least of her concerns. Authorities now want to ask Kate if El Chapo secretly invested in a tequila company that she is an investor in. Really, they want to know if the money is laundered.
Kate currently lives in Los Angeles but if she returns to Mexico, she could be detained for questioning. TMZ said Kate wants to return to Mexico, but she'll refuse to go back until the investigation is closed.
The website also quotes sources close to Kate that claim she and El Chapo have no financial involvement.
Kate has mainly remained quiet about her and Sean's clandestine meeting in the Mexican jungle.
However, on Jan. 13, she broke her silence, at least on social media.
"Thank you for your support over the past days," she tweeted in English and Spanish. "Not surprisingly, many have chosen to make up items they think will make good stories and that aren't truthful. I look forward to sharing my story with you. Kate del Castillo."