Gabrielle Union's basketball star boyfriend Dwyane Wade is facing further problems in his custody battle with his ex-wife after she accused him of failing to keep tabs on his children's asthma medication.

The Miami Heat player, who is currently dating Bring It On actress Union, has been embroiled in an ongoing legal spat with Siohvaughn Wade, the mother of his two sons, since their split in 2007.

The sports star was awarded custody of the boys in 2011, but Siohvaughn has now filed legal papers accusing him of failing to keep up with the medication needed to control the kids' asthma.

In the papers, obtained by, Siohvaughn alleges her former partner has "never obtained any asthma inhalers or asthma nebuliser machines for the children since... he was awarded... custody on March 11, 2011".

The website reports she wants the court to order him to be more attentive and amend her visitation rights over claims the sports star hasn't been adhering to the guidelines set out for her time with the children.