Pensioner, 76, who killed his neighbour’s Koi Carp fish with oil and detergent reveals moment he ‘snapped’
A 76-year-old man from Barnet, north London, has described how he "snapped" after months of sleepless nights caused by his neighbour's noisy pond pump, leading him to kill several Koi carp by pouring motor oil and detergent into the water. Gerry Duffy, who has Chronic Obstructive Pulmonary Disease, admitted the offence in court and said the act was driven by exhaustion and frustration rather than malice, though he says his "revenge" backfired as the pond is now louder than before.
Duffy first poured motor oil into neighbour Andreas Ptohides' pond on 20 March 2026, and four days later was filmed on CCTV climbing into the garden on Hadley Road, damaging pipes and the electric pump before adding detergent, which he says was washing-up liquid. Around five to six fish died as a result. The pair had previously been on friendly terms, but relations soured over the pump's noise; Duffy says a council inspector found no issue and advised him to move or shut his windows, leaving him feeling he had "no choice" but to act after a confrontation with his neighbour at 2am.
- Pensioner Gerry Duffy, 76, killed neighbour's Koi carp with oil and detergent.
- He blamed months of sleepless nights caused by a noisy pond pump.
- Council found no noise issue; Duffy says pond is now louder.
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Barnet, in north London, has become the setting for a dispute between neighbours that ended up in court after a pond was deliberately contaminated. The man involved, Gerry Duffy, is a 76-year-old with a lung condition, while his neighbour, Andreas Ptohides, owns the Koi carp pond at the centre of the case. The two had got on well until the noise from the pond's pump became a source of conflict between them.
The case matters because it highlights how a seemingly minor neighbourly irritant, noise from garden equipment, can escalate into criminal damage and the death of animals, and it raises questions about what recourse residents have when informal complaints and council involvement fail to resolve a dispute. It also touches on the pressures faced by older or vulnerable residents dealing with prolonged sleep disruption.
The broader context includes an earlier council inspection that reportedly found no breach of noise rules, leaving Duffy feeling he had no formal way to address the problem before the incident escalated to CCTV-captured criminal damage.