Los Angeles, Apr 27 (IANS): Singer Kelis has accused her former husband and hip-hop artiste Nas of mentally and physically abusing her during their marriage.

The former couple got married in 2005 and divorced in 2010. The "Milkshake" singer has said she made the decision to leave him while she was pregnant with their now-eight-year-old son, Knight, because she didn't want to bring her child into the alleged abusive environment, reports aceshowbiz.com.

"There was a lot of mental and physical abuse. An intense low... we had a lot," she told HollywoodUnlocked.com.

She added: "It was really dark. A lot of drinking. A lot of mental and physical abuse and it got to the point where if I wasn't pregnant, I might have stayed with him. I was pregnant and it was a mess and I felt like I wasn't going to bring a child into this."

Kelis also claimed frequent alcohol and drug use led to turbulence during the relationship and they never had a "normal" time together.

"We had really intense highs and really intense lows. It was never normal... An intense high would be when money was rolling in. But I was 22 when I met him. We were drinking a lot, getting high a lot. So when that comes down, it was bad," she said.

The 38-year-old says they both physically assaulted each other, but she made the decision to leave the rapper after she saw the pictures of singer Rihanna following her domestic violence assault at the hands of her then-boyfriend Chris Brown in 2009.

Kelis and Nas are currently locked in a custody battle over Knight and in the interview she hits out at her former husband for allegedly not being consistent about spending time with their son.