The incident took place at Central Metro Station in Newcastle, when the man entered holding two items that looked like the popular Henry vacuum cleaners.
He threw them on to the track, causing an obstruction, before walking off.
It took place at 4.50am on Thursday August 8, and Northumbria Police, who described it as "an unusual case", are keen to speak to the man to help them clean up the matter.
The force released a photo of a man, saying: "He may have important information about the incident."
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