The fact that his renditions of 'Twinkle, Twinkle Little Star' and 'How Much is That Doggy in the Window?' are faultless has not impressed them. They are unmoved by his talent for blowing out candles and firing darts.
Insurance companies - which have from time to time provided cover for manically depressed comedians, rock stars with a death wish and jugglers with a drink problem - have refused to insure Mr Methane's bottom.
When he is not dressing up in a green Superman outfit Mr Methane is Paul Oldfield, a 6ft 7ins former train driver, who earns his living from his stage act. Mr Oldfield, 27, can break wind at will, an art first perfected by the French performer Joseph Pujol, alias Le Petomane, a century ago.
Mr Oldfield discovered his rare skill while doing yoga exercises 12 years ago. He found that it made people laugh, particularly fellow British Rail workers, who never managed to run trains with such regularity.
He is able to pass wind in time and in tune with a selection of modern and classical pieces and is particularly in demand for performances of 'Happy Birthday to You' at birthday parties.
Mr Oldfield said: 'If they could insure Liberace's hands, Betty Grable's legs and Samantha Fox's breasts, why not my derriere?
'It is my bread and butter and I am just worried that I could fall ill, or anything could happen, and I would not be insured.'
David Store, an insurance broker, said: 'The problem is that underwriters could not prove, and nor could they disprove, whether his occupation had really been affected by disability. It could be open to fraud.'
The Association of British Insurers said: 'It would be as hard to assess a loss of this man's talent as it would a loss of taste for a wine taster.'