An ambulance was also pictured at the scene.
The crash reportedly involved a car and a lorry.
Sussex Roads Police officer Tom Van Der Wee said it was a 'minor-injury crash'.
The road had reopened by 2.20pm but traffic remained heavy in the area.
PC Van Der Wee's post on Twitter added: "I’m remaining on scene to facilitate vehicle recovery."
National Highways: South-East also issued a statement on social media. It read: "Please allow extra time for your journey as residual delays of 15 minutes remain through the area."
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