London - Britain's Prince William, already under fire for using sorties in Royal Air Force helicopters to visit his girlfriend and go out to parties, was Wednesday reported to have undertaken flights over royal palaces as well.

The prince, 25, who graduated from a three-month training course in the RAF earlier this month, flew a Chinook helicopter over the estates of Sandringham, in south-east Britain, and Highgrove, in the south-west, where his father, Prince Charles, lives, the Sun newspaper said.

It was reported last week that the prince landed the aircraft in a field near the family home of his girlfriend, Kate Middleton, and flew to a stag party of a relative in the company of his younger brother, Harry.

The use of training flights in this way has infuriated Royal Air Force chiefs, who hear daily complaints from airmen that troops in Afghanistan are short of Chinooks in their fight against the Taliban.

The Ministry of Defence (MoD) has admitted there had been "a degree of naivety" in how the training flights would be perceived by the public but said they were all carried out under supervision as part of the Prince's training.

"All flights undertaken with Flying Officer Wales were planned, briefed, authorized and flown by him, under appropriate supervision, in accordance with extant regulations and were accommodated within his planned flying programme. He was accompanied at all times by a senior pilot instructor and experienced aircrew," the MoD said. (dpa)