Gold dropped to its lowest since late December as the euro sank against the US dollar on worries that a worsening debt crisis in Greece could spill over into its neighbours and threaten the existence of the single currency. Gold was down $3.80 an ounce at $1,552.85 by 0620 GMT on Tuesday after hitting a low of $1,547.99. Early bargain hunting, however, had sent prices to a high of $1,559.33 an ounce.