The victim was at Aldi in London Road on December 23 at around 3pm, when she was approached by the suspect, who offered to help her with her bags.
When they arrived back at the victim’s address nearby, the suspect allegedly sexually assaulted her.
An Essex Police spokesman said: “Investigating officers have followed a number of lines of enquiry are now in the position to release an image of a man who we want to speak with.
“Anyone who recognises this man or have any information which could support our investigation is asked to contact Essex Police.”
Submitting a report on the force’s website or by using our online Live Chat service available Monday to Friday (excluding public holidays) between 10am and 9pm.
Visit www.essex.police.uk/digital101 to find out more about the website reporting services.
Alternatively, call Essex Police on 101. In an emergency always call 999.
To make an anonymous report, contact independent charity Crimestoppers by visiting their website or by calling 0800 555 111.
Quote incident 863 of 23 December when providing any information to make sure it gets to the right person as quickly as possible.