if you mean dan, he is still there but they split up 1st after he gambled all their money away, they got back together and then split up again after he found out she snogged his better looking brother!
if you mean vinnie, it was assumed he died but he is living elsewhere with a new identity.
Vinnie was sent to prison for fraud but his dad had set him up. There was a fire at the prison and Leah was told that Vinnie had died. Peter told her later, that Vinnie was still alive and he wanted her to go away with him, but by this time I think she was already involved with Dan, so she stayed in Summer Bay.