Lindsay Lohan has reportedly been pleading with Olympic swimmer Michael Phelps for a date.

The actress - who is rumored to be dating DJ Samantha Ronson - is said to have bombarded the U.S. gold medal winner with calls and text messages asking him to take her out.

And his cool response hasn't put her off - because the more he ignores her, the harder she tries.

A source tells Britain's Daily Mirror, "At first he thought it was a joke when she got in touch. But she's since been phoning and texting constantly."

"It's become a running joke in his camp. Lindsay has been trying to meet up with him. They're both going to the MTV Video Music Awards next month so they'll be sure to see each other properly then."

"Phelps is certainly flattered by all the attention but it's not clear how seriously he's taking it all."