CARMEL, Ind. -- One of two illegal immigrants who were arrested in a drug-dealing sting last week is a major drug dealer and the subject of a multistate investigation, police said Wednesday.

Police said Librado Plata, 24, and a woman who lives with him in Carmel, Sheila Varo, 23, were arrested Nov. 21 on suspicion of selling 1 kilogram of cocaine to a police informant for $20,000 on Indianapolis' northeast side.

When investigators searched their Carmel home several days later, they found and seized 200 pounds of marijuana, Carmel police Maj. Randy Schalburg said.

Plata was a target of a multistate investigation and is suspected of "moving hundreds of pounds of cocaine and thousands of pounds of marijuana over the past several years," Schalburg told 6News' Jennifer Carmack.

Police said Plata and Varo are in the United States illegally, and that the seized drugs came from Mexico.

In Marion County, both Plata and Varo face class A felony charges of dealing cocaine. In Hamilton County, they face class C felony charges of dealing marijuana.

Plata was being held Wednesday with bond set at $500,000. Varo was being held with bond set at $60,000.