The son of tragic Bee Gees star Robin Gibb has welcomed what would have been the Staying Alive singer's first grandchild.

Robin-John Gibb's girlfriend Megan Golub gave birth to little Maxwell-Robin John Gibb on Tuesday (17Jul13).

The new dad, 28, says, "It is an incredible feeling... (but) I wish my father was alive to see his first grandchild. He would be very proud, but I feel sure he knows about him."

Robin lost his battle with kidney and liver failure in May, 2012, at the age of 62.