Wiz Khalifa is seeking joint custody of his son with Amber Rose.

The 27-year-old rapper, who split from the 30-year-model on Monday (22.09.14), contested his estranged wife's bid to gain sole legal and physical custody of Sebastian, 19-months, in new court documents filed in Los Angeles today (26.09.14) and has hired high profile lawyer Laura Wasser to represent him in their increasingly bitter divorce.

Like Amber, the 'We Dem Boyz' hitmaker wants their prenuptial agreement to be enforced, according to gossip website TMZ.com, and has also agreed to pay her spousal support.

Sources said their prenuptial contract states she will receive upwards of $5,000 per month.

Another insider recently claimed the blonde beauty, who previously dated Kanye West and recently signed up to Nick Cannon's management firm, will receive more than $1 million as part of their divorce settlement.

Amber recently slammed ''fake'' rumours claiming she had grown close to Nick, 33, following his recent split from Mariah Carey.

She wrote on Twitter: ''Please stop with the fake stories. I would never ever ever cheat on my husband in a million years I think u guys know this.....

''Unfortunately my now ex husband can't say the same....

''I'm devastated and crushed but my main focus is Sebastian. Thank u for all the support in this difficult time.(sic)''