Mo Farah's wife Tania pregnant with couple's third child

The wife of double Olympic champion Mo Farah has announced that the couple are expecting their third child.

The British long-distance runner reposted an Instagram picture uploaded by partner Tania, who is the mother of the athlete's twin girls Aisha and Amani.

Tania showed off her growing bump and added the caption: "Gained a bit of weight this summer! Looking forward to the next one #Farahbabyontheway."

Farah, who is stepfather to Tania's 10-year-old daughter Rhianna from a previous relationship, also tweeted a photo of his family, adding: "So excited to have baby number 4 on the way!!! Yeeeeeeeeeeezzzzzzzzzzzz!!!!"

The couple have been married for five years.

A photo posted by @taniafarah86 on Jul 30, 2015 at 8:25am PDT

.So excited to have baby number 4 on the way!!! Yeeeeeeeeeeezzzzzzzzzzzz!!!! pic.twitter.com/ApPtESsNyI

— Mo Farah (@Mo_Farah) August 3, 2015