Unidentified goblin killed by Voldemort

A Unidentified Goblin was told on May 1 in 1998 Lord Voldemort about the 1998 Break-In of Gringotts Wizarding Bank. When he heard this, Voldemort was angry, because he know that Harry Potter know about his Horcruxes, and he killed the Goblin with the Killing Curse, to gether with some other presents.

Behind the Scenes
It is possible that this Goblin was worked for Gringotts Wizarding Bank, because he was know about the Break-In.

Appearances
Harry Potter and the Deathly Hallows