Venus and Serena Williams are planning to join forces in the Australian Open women's doubles competition for the first time in five years.

The American sisters have proved to be an almost unstoppable force when they team up even though they only play doubles for fun and rarely practise.

The pair usually need wild cards to get into events because they do not play enough to have a ranking but they have still won six grand slam titles, two each in Melbourne and Wimbledon and one at the French and US Open.

They also struck gold at the 2000 Olympics and are one of only five pairings who have won all four women's grand slam doubles titles.