Dumaka has smashed in 12 goals in his first seven games for Grays this season, helping them into fourth place in the Isthmian Premier Division table.
Dumaka is just 21-years-old, and his pace and power have torn apart defences in the non-league system, allowing him to catch the eye of those higher up the footballing food chain.
West Ham are keen to invite him to train with them, but at the moment the prolific front-man is out injured.
The Hammers have the likes of Andy Carroll, Enner Valencia and Diafra Sakho available to them at present, and for Dumaka to force any of those players out of the team would be a major achievement.
Only Manchester City have scored more goals than West Ham in the top-flight this season, but Slaven Bilic is reportedly looking to add further firepower to his ranks.