Report: Chargers being investigated for using illegal substance By SPORTS NETWORK

Broncos quarterback Peyton Manning (18) is brought down by Chargers linebacker Shaun Phillips (95) and defensive end Corey Liuget (94) during their game in San Diego on Monday, Oct. 15, 2012. (Mike Blake/Reuters)

The San Diego Chargers are being investigated by the NFL for using "Stick 'em" during Monday's game against the Denver Broncos.

According to Fox Sports' Jay Glazer, a Chargers equipment man was reportedly seen handing out little hand towels on the field with the illegal substance inside.

A line judge saw the towels and had them confiscated. They have since been sent to the league.

San Diego blew a 24-0 halftime lead against the Broncos and lost, 35-24.