Pregnant star Britney Spears is being sued over a song. This time Indiana songwriter Steve Wallace acts as a plaintiff, claiming that he is the author of the pop diva's hit Sometimes.

Mr. Wallace, who writes country, gospel and pop songs and now suffering from dystonia which prevents him from talking, according to his attorney’s words, allegedly wrote the song 15 years ago, eonline.com reports.   

The 34-year-old songwriter had no opportunity to obtain a formal copyright and made a simple trick by putting the lyrics of the song in an envelope and mailing it to himself, sealed in an envelope, to get a postmark.

Steve Wallace claims he shopped the song to publishers in 1994 and submitted it to a lyrics contest in Pennsylvania in 1997. A side-by-side comparison shows that the lyrics are nearly identical to the ones Spears sings in her version of Sometimes, featured in her debut album  ...Baby One More Time and Greatest Hits: My Prerogative. Britney Spears obtained a U.S. copyright for the song on January 22 in 1999.

The songwriter‘s attorney John Ritchison has filed a suit on May 5 in federal court against the singer, her album promoter, Sony/BMG Music Publishing Inc., and recording and publishing companies affiliated with the singer.

Wallace is now seeking $150,000 for each instance of copyright infringement.

Meanwhile, the happy couple, Spears and Federline, are anticipating the release of their reality show Britney and Kevin: Chaotic, which premieres on Tuesday. According to Britney's letter on her Website, the series is a response to "constant rumors and inaccurate speculation about our lives together".