Nop, that statement is one big hoax. I tried googling it and I got the whole article
http://tvserialnews.com/tag/omkara-and-ishana/
According to which, Omkara is being suspected or Gayathri's murder which dates long back. I seriously suggest you take this down because I can feel disappointment panging at my chest and I don't want poor other readers to go through the same!