Singer/songwriter Gary Barlow has used Korg musical equipment Credit:LEON NEAL/AFP “We are a very small part of the overall music industry and we are concerned that we have warranted this investigation.” The world-famous guitar maker Fender and four leading keyboard manufacturers are at the centre of a price fixing investigation after “dawn raids” were carried out at their British offices.In total, four keyboard companies and the American guitar giant were targeted by staff from the Competition and Markets Authority (CMA).Although the companies have not been officially named, The Sunday Telegraph understands they include Yamaha, one of the biggest musical instrument manufacturers in the world, Roland, Korg, Casio and Fender.The CMA website states that five separate “initial investigations” have been launched into “suspected breaches of competition law by various parties”. It adds that inquiries “relate to alleged anti-competitive agreements and/or concerted practices in relation to musical instruments and equipment”, adding that it is focusing on “suspected anti-competitive agreements”.The investigations all began in April, when CMA officers arrived unannounced at the five offices. Its officers can enter a business without needing a warrant and demand documents.However, the CMA stresses that the investigations are “at an early stage and no assumptions should be made that competition law has been infringed”. After the initial “information gathering” operation, the CMA will decide whether to open a formal investigation. The inquiry is thought to be focusing on whether any attempt has been made to manipulate sales of musical instruments and pro-audio equipment with, among other things, price fixing or controlled sales to specific areas of the country.A music industry source said as many as 10 CMA staff visited the offices of the music manufacturers, some carrying out searches for up to four days. Meanwhile, 14 leading music shops have been asked to provide details of their dealings with the companies. The shops are not under any suspicion of wrongdoing.The sale of musical instruments and sheet music in online and from shops is worth around £500 million a year in Britain.A CMA spokeswoman said: “We are in the initial, informal evidence gathering stage of five investigations in the musical instrument sector.” Yamaha, established in 1887, produces high end electric guitars, pianos, synthesizers, drums and stringed instruments.Roland makes keyboards used by top musicians including the Brockett Parsons who performs with Lady Gaga. Korg is also a famous keyboard manufacturer with the likes of British pianist Rick Wakeman, who played with Yes, and Gary Barlow, from Take That, using their gear.While it is not clear what triggered the investigations, one music industry insider said it may be linked to a complaint from Germany. Spokespeople for the UK operations of Fender, Yamaha, Roland and Korg refused to comment. Casio failed to respond to repeated telephone calls and emails.In response to the inquiry the Music Industries Association (MIA), the UK trade body for the musical instrument industry, reissued advice explaining the intricacies of competition law.It advises both suppliers and retailers not to agree with one another to sell an instruments at a set price or denote specific geographical areas as exclusive to one store.The article warns that the CMA can carry out “dawn raids” on businesses it suspects may have rigged the market, adding that staff should not shred any documents.“Any business, regardless of its size, could be under suspicion, and subject to a dawn raid. All staff should cooperate with the lawful requests of the investigators (not doing so is an offence in itself),” it says.It warns that breaking competition laws can see companies fined up to 10 percent of their global turnover, prison terms of up to five years and company directors being disqualified for up to 15 years.Paul McManus, chief executive of the MIA, said: “As the trade body for the UK musical instrument industry we have naturally offered all possible support and help to the CMA in their investigation. UK offices of Fender, the American guitar manufacturer, have been visited by Companies and Markets AuthorityCredit:Dan Kitwood/ Getty Images David Gilmour with his Fender Telecaster guitarCredit:Steve Gillett/Livepix Fender has been a household name since its iconic Stratocaster was the instrument of choice for guitar heroes including Jimi Hendrix, Jeff Beck, David Gilmour and Eric Clapton. The instrument was designed in the US in 1954 by Leo Fender. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.