Rope holding together jumps has been cut several times in the past year, and has the potential to endanger horses and their riders when using the course.

Equestrian centre president Liz Sayers said the damage was malicious, and in some cases rope supporting the log jumps had been left hanging by a thread.

"The idea of the ropes is that they can be cut in an accident if a horse falls," she said.

"It has been happening for the past year. I had to replace them all three weeks ago and it's a worry because the kids aren't going to notice rope partially cut and could be hurt if it fell while they were using it.

"It could cripple a horse if it fell when somebody was using it."

Mrs Sayers said the latest attack had forced management to close the jumps course for at least the next two months because logs were rolled off their supports.

An inspection of the jumps supports will now have to take place because of the latest damage.

"Our endeavour is to bring this course to a state level standard," Mrs Sayers said.

"If somebody wanted to hire it out we would have to knock them back and lose that revenue."

Smythesdale Police Leading Senior Constable Craig Grenfell said the damage was not fair for the volunteers, who manage the facility.

"It's just stupid acts you would hope wouldn't continue," he said.

"They are a voluntary board and the money that they raise and it is very disappointing."