Singer Kelis has slammed her rapper ex-husband Nas after his attorney allegedly insulted her legal representative as a "fattie" during a child support deposition.

The Milkshake hitmaker has taken Nas back to court to demand more cash to support their eight-year-old son Knight, and she recently sat for questioning by the hip-hop star's legal team to further her case.

However, Kelis claims the deposition was far from professional, with Nas' representative reportedly resorting to childish name-calling during the session, which was cut short due to the inappropriate behaviour.

In legal papers obtained by, her lawyer, Navid Moshtael, expresses his outrage at allegedly being criticised over his weight and branded a "d**k", insisting that while he is used to insults, fielding them from an "experienced attorney" in front of clients and on the record is a career first.

The documents also suggest Kelis is unwilling to sit for a new deposition, insisting Nas' lawyers blew their opportunity to gather evidence from her.

Kelis and Nas, who divorced in 2010 after five years of marriage, have had a strained relationship of late after the One Mic MC accused his ex of only allowing him visitation with Knight "when she deems it convenient for her".

He asked a judge to put an official custody schedule in place in November (17), but the issue was soon resolved after he and Kelis reached their own visitation settlement, granting Nas weekends with his boy.

However, the custody dispute heated up again last month (Feb18), when Kelis claimed the rapper should be paying her more than the $8,000 (£5,700) a month in child support they agreed upon five years ago, when their son Knight was three, insisting the kid has needs he didn't have when the deal was signed.

Kelis hasn't come up with a specific figure but she does want her ex to pay half of all Knight's education costs, child care and health-related issues.