Naomi Watts has prompted speculation she and boyfriend Liev Schreiber have married in secret in Australia, by showing off a ring on her wedding finger.

The pair have been in Watts' homeland while her beau shoots new movie Wolverine there.

But Australian newspapers are speculating they took time out to tie the knot during Watts' trip down under to visit Schreiber - after a snapper caught the actress "wearing a large diamond ring and another band with smaller diamonds on her ring finger" as she arrived back in Los Angeles on Monday.

The couple were forced to issue a statement denying they had married in June 2007 after Schreiber joked to reporters, "We are married. You got it first. Break the story!"

This time around, Watts' representative is refusing to confirm or deny the reports, telling New York gossip column PageSix.com, "I don't comment on her personal life."