The packages labelled "Uranium. Medium radiation" prompted National MP Katherine Rich's electorate secretary to call emergency services, followed by a three-hour evacuation of the second storey of Radio Otago House.
Specialists from Public Health South found the contents of the packages - including two left at the Green Party offices in lower Stuart St - did not present any risk to public safety.
Mr Belcher (45) said he delivered two plastic bags, each containing a vial of monazite sand (made of phosphates and containing rare earth metals, including elements thorium) and a piece of loveringite, an iron/titanium/uranium ore, to the National and Green Party offices about midday.
The Dunedin city councillor from 1998 to 2004 said he was back in Dunedin on a 12-day holiday and had brought the "information packs" with him from Australia, where he works as a geologist, to show politicians an alternative solution to New Zealand's power supply issues.
Thorium is a rare earth metal that can be used as fuel for nuclear power if it is bred into uranium-223.
Mrs Rich's electorate secretary, Robyn Broughton, said Mr Belcher had told her what was in the packages, but she had not comprehended the possible danger until, after he left, she read the label indicating they contained medium-level radioactive material.
"If it said low-level or trace radiation, I wouldn't have been so worried."
She was shocked because Mr Belcher said to her "Tell Katherine to give it to the kids to play with", then said he was just kidding, she said.
A spokesman from the Green Party office said he was not so concerned about the packages, because he knew the uranium ore had only low-level radiation.
The label on the package was "slightly misleading" and could have prompted others to have greater concerns.
