Lindsay Lohan accuses Samantha Ronson of cheating

Lindsay then appeared to confirm her relationship was over, writing: “look, im doing this publicly because u+ur friends call people mag..so-you win, you broke my heart. now go away. i loved you (sic)”

Lindsay – who has completed three stints in rehab and sparked fears for her health recently after losing a dramatic amount of weight – then took a swipe at Samantha’s twin sister Charlotte.

She wrote: “ask ur sister 2 stop yelling profanity plz;;stop doing drugs. and tell charlotte to do more-she could loose a stone or 10 (sic)”

Lindsay’s online rants come days after she was refused entry to Charlotte’s party

Samantha was playing a set at her sister’s bash at Los Angeles’ exclusive Bar Marmont, but when Lindsay arrived she was turned away by five members of security at the door.

The actress was reportedly so desperate to gain entry she even tried to climb over the walls.

A source told gossip website X17Online: “Eventually Lindsay's friends, the D squared designers who were staying at the Chateau, took pity on her and said they would look after her so they let her into their rooms. But the minute they let her in, Lindsay tried to sneak into the party again! Poor girl just couldn't get in.”

It has been claimed Samantha’s family had told the security guards not to let Lindsay enter the bash.

Samantha has since changed the locks on the Hollywood Hills house she shared with Lindsay.

A source said: “I'm sure Lindsay and Sam are over. Sam's family wants her to get away from Lindsay - they think she's completely nuts!"