Kristen Bell and Dax Shepard have announced they are expecting their second child together.

The 33-year-old Veronica Mars actress became a mother to daughter Lincoln in March 2013 and has spoken about how much she is loving motherhood.

A spokesman for the couple told Entertainment Tonight: "I can confirm that Kristen and Dax are expecting their second child and a sibling for Lincoln. The whole family is beyond excited."

Kristen and Dax, 39, have been dating since 2007 and announced their engagement in 2010. But they pledged not to tie the knot until same-sex marriage was legalised, so Dax proposed again on Twitter on June 26 last year. They were married in a low-key ceremony in October.

Since becoming parents they founded the No Kids Policy, which aims to get news outlets to stop sharing, buying or posting photos of celebrities' children taken without consent.

Kristen told the Huffington Post: "I've heard from a couple different people who certainly get stalked much more significantly than we do that it's quite literally changed their day to day lives with their kids.

"I'm a firm believer that all we have is our collective consciousness. Moms especially, but parents and informed consumers just decided it was a line that shouldn't be crossed. We've started to see the results and I'm very grateful for it. I think it makes for a more positive media monster."