Hi..yes he can claim his fathers medals. You have to write to the Medals Office at RAF Innsworth which is near Gloucester. Provide as much info as you can..name, rank, number etc. If your friend is the direct living decendant then he can sign the forms if his mother is still alive then she would have to sign.
I claimed my grandfathers medals a few years ago as he served in Burma during WW2 and on his return never spoke much about his time and got on with his life. He died 15 years ago and we decided to claim them and present them to my Nan. We got her to sign the form using a bit of deception! Took about four months but then a small parcel arrived and in it contained a small medal box with his medals and ribbons..just as they would have been sent all those years ago. The box had his name rank number on it and it was very moving. We had them mounted and displayed in a case with a small brass plaque. When we gave it to my Nan she started to cry and we all got very choked up..but it was such a nice thing to do..we were all very pleased.
If i can find the paperwork ill let you know the exact address but a bit of digging on the net should reveal it.
Andy.