Grammy-winning R&B singer and "The Voice" TV judge CeeLo Green pleaded not guilty on Monday to a felony charge of giving the drug ecstasy to a woman without her knowledge while the two were dining, prosecutors said.

Green, whose real name is Thomas DeCarlo Callaway, was charged by the Los Angeles County District Attorney's Office with one count of furnishing a controlled substance.

Green entered the plea in a Los Angeles court and faces up to four years in state prison if convicted.

The singer "slipped" ecstasy to the 33-year-old woman while the two were dining at a Los Angeles restaurant in July 2012, according to prosecutors.

The woman said she did not know that Green had given her the drug, said Jane Robison, a spokeswoman for the district attorney's office.

Ecstasy is a lab-produced drug that acts as a stimulant and can cause hallucinations.

Green, 39, and the unnamed woman went back to her hotel room after dinner, prosecutors said.

Celebrity website TMZ.com reported last year that the woman had filed a police report accusing Green of sexual assault. Robison said the alleged victim had contacted the police.

Prosecutors, however, said there was insufficient evidence to charge Green with rape of an intoxicated person.

Green's attorney, Blair Berk, said she was happy the "evidence did not support the false and unfounded claims made over a year ago."

"Mr. Green encouraged a full and complete investigation of those claims and he was confident once conducted he would be cleared of having any wrongful intent and it would be established that any relations were consensual," Berk said in a statement.

"As it relates to the one charge of furnishing or sharing ecstasy, Mr. Green will responsibly address that matter in a court of law but not comment on it further out of respect for the process," she added.

The singer was ordered to post $30,000 to remain free on bail, and is due back in court on November 20, Robison said.

Green, a Georgia native, is best known for his 2010 hit song "Forget You," and is a judge on "The Voice," NBC's reality singing competition. He is also half of soul music duo Gnarls Barkley, best known for songs such as the 2006 smash hit "Crazy."

He has won five Grammy awards including three as a solo artist.