A man clad only in stockings and suspenders was chased through a forest by police for 30 minutes before being arrested.
The pursuit took place in broad daylight in woodlands close to public playing fields in Londonderry.
Two women out walking in the area came upon the man dressed in tights and suspenders and nothing else last Tuesday.
Police confirmed a 59-year-old man was arrested in the Victoria Road area on suspicion of indecent exposure. He was questioned and released on police bail pending further inquiries.
Derry councillor Maurice Devenney said the incident was an example of the deviant sexual behaviour taking place in the Prehen area of the city. The councillor said such incidents were now a nightly problem with up to 150 adults gathering to indulge in sexual and deviant activity in the Prehen and Ness woods areas.
Mr Devenney said local people were sickened by the lewd behaviour of what he believed was a well-organised underground network. Police said they were aware of the concerns and have urged any local people with suspicions to contact them.
The arrest is the latest shocking episode at the beauty spot and adds to concerns over 'dogging' and other extreme sexual behaviour in the Prehen and Ness areas, both of which are popular walking areas for families.
The two areas appeared as meeting hotspots on a swingers' website as far back as 2008.
Mr Devenney said: "There are nightly events now in these woods and it is very much an issue at the moment.
"We have playing pitches here where this is happening and we are going into the Derry & District League now when there will be some young people changing out there, and the last thing we want is characters like this out there," he added.
"The football pitches are in ownership of Derry City Council and I have spoken to the council to see if we are the owners of the land beside that area.
"I am hoping we do not get a situation where we have to put up gates, as we wouldn't want anybody to come upon something like that."
Mr Devenney said that he had raised similar concerns two years ago with police and that the issue seemed to have been dealt with at the time, but has since resurfaced.
A spokeswoman for the PSNI said: "Waterside neighbourhood team is aware of the concerns raised by the local councillor and will be making further inquiries with a view to keeping Mr Devenney fully updated.
"We would appeal to local people to report any suspicions they have and if vehicles are involved, note details of the vehicles and their registration numbers."
A spokeswoman for Derry City Council confirmed that it was aware of the concerns raised by councillor Devenney.
She said: "Derry City Council will work closely with the PSNI in relation to reporting any anti-social behaviour."