Could high oestrogen levels in a males body affect his libido?

YES. Increased estrogen in men can be caused by increased adipose (fat tissue) and testosterone replacement therapy, although not exclusively. Both men and women produce estrogen, but in much different amounts. Elevated estrogen in men can reduce libido and cause other unwanted health related problems. Weight loss can help reduce estrogen levels. If on testosterone, dosage adjustment may be needed.
Definitely. Normally, men have estrogen but if the levels are higher than normal (very rare without supplements or tumor), the libido can be depressed.