Canadian pop singer Avril Lavigne has dismissed allegations that her hit single "Girlfriend" is taken from a song called "I Wanna Be Your Boyfriend" by the power pop band the Rubinoos.

"I had never heard this song in my life and their claim is based on 5 words," Lavigne writes in an open letter on her official Web site. "All songs share similar lyrics and emotions. As humans we speak one language."

As previously reported, Tommy Dunbar, founder of the Rubinoos, filed a suit in California's Northern Federal District Court in San Francisco on July 2.

The suit alleges that "Girlfriend" bears striking similarities to the Rubinoos' song "I Wanna Be Your Boyfriend," co-written by Dunbar and former Rubinoos' road manager James Gangwer, and released by Beserkley Records in 1978.

The lawsuit also names as defendants Lavigne's publishing company Avril Lavigne Publishing and Lavigne's co-writer of "Girlfriend," producer/remixer Dr. Luke (birth name Lukasz Gottwald).

Lavigne adds, "I am not going to sit here and defend my writing skills. I don't have to prove anything to anyone. I know who I am and what I have done and accomplished and no one can take that away from me."

Meanwhile, Lavigne's Vancouver-based manager, Terry McBride, CEO of Nettwerk Music Group, has taken a broadside at Dunbar and accused him of lying.

In a July 7 blog posting, Dunbar wrote: "While it's true that we filed suit some time ago, we hesitated to go public to save Avril and her handlers any embarrassment. We learned over the July 4th holiday that her management and spin doctors have apparently decided to pre-empt things with their revelation of the lawsuit."

McBride counters this. "This is simply a lie," he said in a statement. "I challenge them to provide one iota of proof to back up this claim. We did not say a word about the suit out of respect for the dialog that was ongoing. The numerous phone calls from the media seeking comment on the suit started on July 4th. We were blind sided and simply responded."

McBrides concludes, "As we have clearly stated, upon the expert opinion of one of the country's foremost musicologists, there is no basis for this claim."

On her Web site site, Lavigne also addresses comments by fellow Canadian singer/songwriter Chantal Kreviazuk made in the June issue of the U.S.-based magazine, Performing Songwriter.

In the article, Kreviazuk was dismissive of Lavigne's songwriting talent.

Lavigne hit back, "Chantal's comments are damaging to my reputation and a clear defamation of my character and I am considering taking legal action."