The 18-year-old, who is the brother of Hammers youngster Emmanuel Longelo, became a free agent this summer after being released from his contract with the east London side's Under-18 squad.
Longelo, who also spent time in Norwich and Middlesbrough's academy, is predominantly played on the left-hand side of the pitch, either as a defender or midfielder. The teenager has also been used through the middle and on the right.
Now a free agent, Sun journalist Tom Roddy claims that Longelo has put pen to paper on a four-year contract with Newcastle. He adds that the young winger completed his medical at St. James' Park on Friday.
The 18-year-old was also called up to West Ham's Under-23 squad on two occasions. Longelo played the full 90 minutes in a home win against Manchester City as well as their defeat on the road to London rivals Arsenal.
Longelo will be expected to spend a number of seasons in Newcastle's development squad before being given the chance to step up, although the 18-year-old can expect a number of cameo appearances in the club's various competitions.