TAMPA, Fla. — Two state lawmakers are calling for an investigation after the deaths of manatees at ZooTampa. 

The zoo's head veterinarian is no longer allowed to treat manatees after allegations that he harmed the animals. 

U.S. Reps. Charlie Crist and Kathy Castor filed letters this week to Interior Secretary Ryan Zinke demanding a full investigation.

Dr. Ray Ball is being accused of harming manatees due to questionable medical care. At least two manatees died as a result of allegations including improper feeding, drug use and poor emergency care. 

The U.S. Fish and Wildlife Service sent its own letter to the zoo last month raising concerns and prohibiting Ball from treating or handling manatees. 

Zoo officials have until December to respond to the allegations.