"I'm not going to comment on any possible injuries until we have finished our scene examination and have all the details so we can give you an accurate description,'' he told APNZ.
It was not known how long the pair had been dead before their bodies were found, but it was not believed to be long.
Police and forensic teams will carry out a scene examination today.
Mr Gaskin said police were still confirming the identity of the bodies. He would not comment on their ages or whether they were locals.
Post mortem examinations would be carried out once the bodies were removed from the scene.
News from the scene was filtering through slowly because the area was "extremely isolated'' and lacked cell phone or police radio coverage.
"We're just taking it very slowly and making sure we get it right.''
School principal Adam Rivett said he had heard the bodies of a man and a woman were discovered by two riders in a remote forestry plantation.
"It's a very remote area out there and it was a strange place to find them.''
If they hadn't been found, the bodies could have remained there for weeks or more, he said.
The charity event had to be shut down as a result.
"It's not really what you want to do when you're running a fund raiser,'' he said.
The bodies were found about 40 minutes' drive from the Waimate township.
"It's a small place and these sort of things don't happen very often.''
One of the participants, Andrew Wright, of Timaru, told local media another rider put his hand on the man's chest, which was still warm, and tried to stem the flow of blood.
Daryl MacDonald said the man, probably in his late 30s or early 40s, was lying on his side when he was found.
The woman was found in a clearing away from the man, and riders believed she had been there for a while.
Waimate Main School board of trustees chairman Tony McKenzie was taking part in the charity event but said he did not see the bodies.
He said the discovery came as a shock.
"We were having such a good day with the trail bike ride and we had such a good turnout of riders. It doesn't leave a very good feeling now.''
The event had been cancelled immediately.
There were many rumours circulating about what had happened and it was hard to know what was true.
"The police have it all cordoned off so other than that we don't know anything at this stage.''
The Oamaru Mail understood the bodies were found in the Waihaorunga area, an expanse of rolling, forested terrain which groups are sometimes permitted access to for events such as charity rides.