A dozen colts are set to compete in Saturday's Investec Derby headed by the unbeaten Camelot.

The 12-furlong Classic, in its 233rd year, starts at 4pm at Epsom Downs and offers a prize fund of £1,325,000, the most lucrative race in Britain.

Camelot, trained at Ireland's the famous Ballydoyle Stables by Aidan O’Brien, is unbeaten in three starts and comes into the Derby on the back of victory in the opening Classic of the season, the QIPCO 2000 Guineas over a mile at Newmarket on May 5.

If successful at Epsom Downs, Camelot would become the 37th horse to win both Classics and the first since the legendary Sea The Stars in 2009.

The son of Montjeu is currently the red-hot 4/6 favourite with William Hill - the last horse to win the event at odds-on was Shergar in 1981.

Jospeh O’Brien, the 19-year-old eldest son of Aidan O’Brien, is set to ride Camelot.

The strongest opposition to the Ballydoyle challenge could come from the Andrew Balding-trained Bonfire, the 9/2 second favourite.

Main Sequence, the 11/1 third favourite, is set to be trainer David Lanigan’s first runner in the Derby and comes into the race unbeaten in four starts.

William Hill spokeswoman Lucy Rhodes said: "Naturally Camelot continues to be all the rage for Epsom and looks set to jump away the shortest-priced Derby favourite seen in some time, although it’s not unknown to see a big run from an O’Brien second-string and there has been plenty of interest in Astrology this week."

The latest odds for the Investec Derby: 4/6 Camelot, 9/2 Bonfire, 11/1 Main Sequence, 12/1 Astrology, Imperial Monarch, 25/1 Thought Worthy, 33/1 Mickdaam, 50/1 Father Of Science, Rugged Cross, 66/1 Minimise Risk, Tower Rock, 100/1 Cavaleiro.