A teenage boy was indecently assaulted as he walked along a quiet Mid Sussex path.
The 14-year-old was grabbed from behind by a man who touched his trousers.
The boy called out "Help - pervert!" and the man ran off.
The attack happened on the Broadfield Brook footpath leading to Broadfield Stadium, Crawley, between 1.45 and 2.25pm on Wednesday.
Police are appealing for witnesses.
Detective Constable Becky Harris said: "I am particularly interested in tracing a man who was walking his dog near the Broadfield Stadium at this time as he may be a possible witness."
The attacker is described as about 6ft tall, in his 40s, with black rough or fluffy hair.
He was wearing an orange fluorescent jacket which looked quite new, black trousers and black training shoes.
He smelt musty and had grubby hands and a wrinkled face. He did not speak during the attack.
Anyone with information is asked to contact Ms Harris at Crawley CID on 0845 6070999.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article