Lindsay Lohan has passed two drug tests.

The actress - who was ordered by a court to agree to random screening under the conditions of her recent probation hearing for driving under the influence (DUI) convictions - is said to be doing well in her bid to stay sober.

“She is clear of illegal substances. She has already taken two tests and passed both,” a source revealed.

The 23-year-old star - who was also told she must wear an alcohol-monitoring SCRAM bracelet - has impressed her parents with her bid to stay “on the straight and narrow.”

Her father Michael Lohan - who has repeatedly claimed the actress needs treatment for prescription drug addiction - said, “I am happy for her. She’s on the straight and narrow. I hope it continues.”

Michael and ex-wife Dina Lohan - who have feuded bitterly over their famous daughter - appeared before a judge in New York yesterday and claim their ongoing dispute over child support for their three kids is now resolved, leaving them to focus on helping Lindsay.

“I’m extremely happy with the outcome. I felt it was time to put my feelings aside and do what was right. Dina and I have entered into an agreement. I hope this is a stepping stone for us to be united, not only financially, but as parents. With this behind us, we can now focus on Lindsay,” Michael said.