Sequence object does not disappear after deletion

Hello,
I’m going crazy, a long time ago I created a sequence with a basic sphere that moved around the screen to check that the sequence was playing correctly. After that I deleted the sequence, but now the sphere appears, sometimes yes sometimes no, in a completely random place, but without moving. I’ve looked for it to remove it everywhere, but it doesn’t exist!!! I’ve gone through all the sequences several times and checked every element of the Outliner (in edit mode as well as when the game is playing) but it’s not there!!! Does anyone know what I might have done wrong? Wasn’t the sphere animated with a sequence like I remembered? I’m desperate to get hold of it.

Thank you very much in advance