Normally, three viewer puzzles are played in the course of the show, for increasing amounts of prize money. The prize values have varied throughout the show's history; initially they were typically £250, £500 and £750 or £1,000; by 2006, they were usually £500, £1,000 and £2,000 respectively. There were also various occasional twists to this aspect of the show, including other variations in the prize values, having one, two or four puzzles in a show instead of the usual three, and various bonus games (mostly games of chance) by which a caller can win even more money. These are usually themed to an event (e.g. Wimbledon) or a season (e.g. snow). Two kinds of viewer puzzle are regularly featured:  There are also three kinds of puzzles that are occasionally featured instead:  The presenters often give clues to the words to aid those unable to work it out, though these often make the puzzles very easy. For example, on one occasion when the word was 'sister', the presenter said 'This type of nurse might look after you on a ward', and later, 'Michael Jackson has one called Janet'. An addition partway through the programme's lifetime was an extra viewer puzzle announced at the end of the show and again during the commercial breaks of the following programme. This is often a Scramble puzzle, but for a prize of £1,000. In light of the ICSTIS investigation of the use of premium-rate telephone numbers in various interactive British television programmes as part of a phone-in scandal, Cheetah Productions (a division of Endemol), who created the "BrainTeaser" format, admitted that some of the show's contestants were fake. On 8 March 2007, Channel 5 resultantly suspended all shows involving premium rate services, claiming they knew nothing about the scam. However, a simple procedure checking daily winners would have easily identified the fraudulent activity instantly. Channel 5 later admitted that the channel's senior producer was informed by Cheetah Productions that several winners had been fake. The channel ignored this advice and continued to broadcast the show until the ICSTIS investigation was concluded. During this time, Avon and Somerset Constabulary reviewed the reports from Channel 5 and the ICSTIS to see if there were any allegations or evidence of criminal wrongdoing contrary to the Fraud Act 2006. Once the ICSTIS investigation was completed on 26 June 2007, Ofcom handed out a record-breaking fine of £300,000 to Channel 5 for the phone-in scandal.