Gas prices: 'Libor-like' manipulation

FSA EXAMINES GAS PRICE FIXING

UK regulators are investigating an alleged attempt to manipulate prices in the wholesale gas market similar to the LIBOR interest rate fixing scandal in the banking sector earlier this year, The Guardian reports. The Financial Services Authority (FSA) and Ofgem are investigating unusual price activity in late September in the National Balancing Point, a virtual hub that serves as the main pricing point for natural gas. Regulators have to examine whether City traders submitted quotes below the market price in order to force the NBP to fall and subsequently profit from the lower price position in other markets.

First, in my opinion this will be (is) politicized as it offers a good opportunity for politicians to push blame of rising energy prices on unscrupulous energy suppliers and gain scores for next elections.

Second, what is the economic sense to move the benchmark down? As I understand, the suppliers are monitored by OFGEM and have to justify the prices they charge. If retail prices are set against the index, then energy suppliers should be better off moving the index upwards, so that they could justify higher prices with higher costs of energy. I am not an energy expert, so my two assumptions about this strategy(it could all be BS but let's say there indeed was manipulation) would be:

a) The retail price-setting process is garbage. Energy suppliers use percentage increases from the moment index was updated to set prices instead of absolute level, i.e. a 0.8% energy cost increase (58.5-58.0 / 58) is used instead of calculating if price is reasonable for 58p cost.
b) hypothetically someone was short "commodity swap" (seems unlikely unless someone was involved in both physical and financial markets)

More importantly, does a system where for-profit companies resort to benchmarking prices against an index level observed on 28th of September make sense?