(CNN) Popular smartphone apps that assess suspicious moles on people's bodies may not be reliable in detecting all forms of skin cancer, doctors have warned.

A study found that the leading apps were both missing melanomas and incorrectly telling people their moles were a cause for concern.

The researchers evaluated SkinVision and SkinScan, two popular European apps which have not yet been approved for a launch in the United States by the Food and Drug Administration (FDA).

"Our review found poor and variable performance of algorithm-based smartphone apps, which indicates that these apps have not yet shown sufficient promise to recommend their use," wrote the authors, from the universities of Birmingham and Nottingham in the United Kingdom.

They warned that the current regulatory processes "are inadequate for protecting the public against the risks created by using smartphone diagnostic or risk stratification apps."

Read More