The Federal Court in Melbourne has released another batch of key files and documents in the case being run by ASIC against Commonwealth Bank over allegations the bank used the sheer volume of its trading to manipulate the BBSW on at least six occasions.The Australian Securities and Investments Commission alleges that CBA's trading desk and its Treasury department colluded to manipulate key reference rates such as the Bank Bill Swap Rate in whatever direction would be most profitable that day. In other words, CBA could find itself on either side of a trade - whichever gave it the clearest benefit.The crux of ASIC's argument has been that "CBA personnel had knowledge, belief, an understanding or awareness … that the BBSW was susceptible to manipulation, in that it was possible to trade in the BBSW Rate Set Window so as to influence the likely level at which the BBSW for Prime Bank Bills in a particular tenor was set by AFMA, in a way that was likely to be favourable to the corresponding Swaps BBSW Rate Set Exposure and on occasions the corresponding Treasury BBSW Rate Set Exposure …", and that CBA did trade in that manner.CBA denies the allegations, and has yet to have its day in court - in fact the bank needs to see all of ASIC's proposed arguments before it can mount its defence."CBA disputes the allegations made by ASIC as we do not believe our employees have engaged in unlawful conduct, nor have they done anything that would have adversely impacted the efficiency and integrity of financial markets as alleged, or at all," a bank spokesman said."The Commonwealth Bank has co-operated fully with ASIC's investigation and we will look to engage constructively with ASIC in order to resolve this matter."There are ambiguous extracts from emails and messaging between traders (in material filed by ASIC and released by the court yesterday). One of these was a transcript of one exchange on 3 February 2011 between Garfield Lee and Paul Bennett, both at CBA: "At 09:09, Mr Lee said in an email to Mr Bennett, in response to a request for ideas for making more revenue: 'We could more aggressively manage ratesets (buy when we need it low and sell when we want it high) though this is greatly a part and parcel of fixing the funding and liquidity operation...You could increase my limits and let me smash it around [smiley face emoji] (would be bigger P&L outcome in absolute terms, just might be more L than P)'Mr Bennett seems to have said no."And then there is this report of an exchange on 8 March 2011:"At 17:32:45, Mr Dillon said in an email to Ms Newsom, copying in Mr Bennett:I was just talking to Paul and under 'conflict of interest' another way we could explain this to an RBS or PBP Group Executive is:  Treasury's only motivation is to look after your rate set (BBSW) interest to give a cost-effective source of funds where as [sic] with GM