Ministry of Defence bosses have been branded “disgraceful” after admitting that almost 500 wounded troops were spied on by private investigators. Chiefs have been accused of “dirty tricks” after spending taxpayers money for surveillance on people suspected of submitting fraudulent compensation claims. Since 2003, Government lawyers have hired private investigators for £1750 a day to watch 489 individuals claiming millions in compensation. The claims from ex-soldiers are for injuries suffered through training, such as back problems, hearing damage and cold weather injuries. A total of £135m was…