Mischa Barton says she and beau Cisco Adler are not engaged.

The OC star has only been dating Adler for five months, but has been plagued by constant tabloid rumours about the status of her relationship.

TeenHollywood.com says that Adler, who fronts rock band Whitestarr, wears a lock necklace that only Barton has the keys to. She herself wears the keys around her neck.

Adler added: "An engagement is not true. The love is young!"