George Clooney's parents don't know what to buy him as a wedding gift

George Clooney, seen with wife and world-renowned human rights lawyer Amal Clooney, pose in Florence, Italy, on Sept. 7, 2014. The American actor says the Canadian government should do everything they can to free jailed Canadian journalist Mohamed Fahmy from an Egyptian prison. (Francesco Bellini/AP Photo)

George Clooney's parents don't know what to buy him as a wedding gift.

The 'Monuments Men' star - who is worth a rumoured £100 million - will marry human rights lawyer Amal Alamuddin at the end of this month but Nina, 75, and Nick Clooney, 80, are unsure whether the couple would prefer a present of a donation made to a charity of their choosing.

Nina said: "I haven't got them a wedding present yet because we haven't decided what to get, or if they would prefer some kind of donation."

The happy couple are planning to tie the knot in Venice, Italy, and George's mother thinks they have chosen the perfect setting for their big day.

She is quoted by Britain's Grazia magazine as saying: "It is in Venice at the end of this month. We are just thrilled. We have been to Venice before and it is the most romantic place. It will be lovely to see George get married."

The 53-year-old actor recently gushed about his excitement at marrying Amal.

Speaking at an event in Florence, he said: "I met my lovely bride-to-be here in Italy and I will be marrying her in a couple of weeks in Venice, of all places.

"I can't wait to tell Amal, 'I love you more than anything and I can't wait to be your husband.' "