Dalgety Bay was the site of a World War II airfield
The Ministry of Defence has criticised the monitoring of radiation hotspots on a Fife beach, carried out by environment watchdog Sepa.
The Scottish Environment Protection Agency said 39 radioactive items were detected in September at Dalgety Bay.
Radium from wartime aircraft is thought to have been in landfill used when the foreshore was reclaimed.
The MoD said aspects of Sepa's research seemed to be based on "assumptions rather than actual evidence".
Dalgety Bay was the site of a World War II airfield, where many aircraft were dismantled.
The dials in the planes were coated with radioactive radium so that they could be read at night.
It is thought the dials were incinerated along with other waste and later tipped on the land and used to help reclaim some of the coastline.
Numerous surveys have been carried out on the beach since radiation was first discovered in 1990.
The latest Sepa study found "widespread low level contamination of radium on the inter-tidal area".
It said a dose would be low for an adult, but would potentially be significant for a child.
An MoD statement said it would fully meet its responsibilities "in regard to contamination at Dalgety Bay".
"However, we need to talk to Sepa about some aspects of the research, which seem to be based on assumptions rather than actual evidence," it said.
"We want to ensure that land and risk assessments are thorough, so that any future decontamination work provides a permanent solution.
"This does take time, but it is important to get it right."
Byron Tilly, radioactive substances unit manager at Sepa, said: "Sepa's preliminary report on Dalgety Bay contamination recognised that there were a number of uncertainties in any method used to assess the dose consequences and welcomes MoD's proposal for further work in this area.
"In its assessment Sepa used a framework developed for contamination at Dounreay and peer-reviewed by independent experts."
He added: "Many members of the Dalgety Bay Forum, including Sepa, consider that enough time has been spent analysing the problem and the need now is for more positive action to remove the contamination."
Mr Tilly called on Defence Estates, part of the MoD, to come forward with proposals to deal with the contamination.