Water testing samples are still being collected by helicopter at Lake Horowhenua at a cost to regional ratepayers of more than $14,000 so far.

Horizons Regional Council confirmed it had continued to use the method after threats were allegedly made against staff members at the lake edge last year.

The council cited health and safety policy as the reason the helicopter was being used and said work on the ground had been hampered by alleged "physical intervention, aggressive behaviour and threats" towards Lake Accord partners, usually Horizons staff and Lake Trustees, undertaking work or taking part in activities relating to