Germany September import prices +2.1% vs +1.8% m/m expectedPrior +1.0%Germany September import prices +10.4% vs +10.3% y/y expectedPrior +8.3%Just when Germany thought it had enough economic headaches to deal with, here's another one to add to the pile. This time, the inflation monster is making quite the comeback through the back door.German import prices for September are seen rosing at their fastest annual pace since November 2022, with the monthly increase also coming in hotter than expected. And surprise, surprise. Not. It is energy that is once again doing much of the damage.Imported energy prices surged by a whopping 61.8% compared to a year ago, with electricity prices almost doubling (+96.2%) compared to the year before. The US-Iran conflict is definitely leaving its mark on Germany's import bill and businesses aren't exactly getting much breathing room elsewhere either.Prices for intermediate goods rose 11.1% annually, including a 37.9% increase in copper and 23.4% rise in aluminium. And even if you strip out energy prices, import prices were still up by 5.5% year-on-year in September.So, what does this tell us?To start, the details suggest that Germany's imported inflation problem isn't just about expensive oil and gas prices. Higher input costs are spreading across industrial supply chains and that could potentially squeeze manufacturers' margins at a time when the economy can ill afford another setback.And this also spells trouble for the ECB. Now, import prices aren't the same as consumer prices of course. However, sustained increases in energy and production costs could eventually filter through to households, depending on how much businesses can pass those costs along.All in all, this will just be another anecdote in reaffirming the prospects of another ECB rate hike in December - especially with markets already pricing in roughly 61% odds of such a move at this juncture. This article was written by Justin Low at investinglive.com.