A man exposed himself to a 23-year-old woman as she was walking on a footpath with her dog near the beach at Corton Road at Gunton on Tuesday at about 5pm.
The woman then saw the man in some bushes acting in an indecent manner by the playing field near Dip Farm.
The suspect was about 5ft 10in and was wearing a black hooded top and blue jeans.
Anyone with information should call PC 1523 Baker at Lowestoft police station on 01986 835300.
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