At least a fifth of all sexual crimes in Scotland last year happened online, according to a new study.

The review, published by the Scottish Government, also reveals a number of gaps in knowledge about hi-tech crime.

It found evidence cyber-crime is under-reported to the police compared to other offences.

Police Scotland only dealt with 30 incidents of computer misuse - which covers hacking and virus attacks - last year.

However, technology has changed the "scale and nature of sexual crime in Scotland", according to the Cyber Crime in Scotland report published on Friday.

It estimated: "The internet was used as a means to commit at least 20% of all sexual crimes recorded by the police in Scotland in 2016-17."

"We still need to know more about cyber crime in Scotland, such as the prevalence of different types of cyber crime, the extent of under-reporting, the cost and the harm of cyber crime," it added.

"Furthermore, little evidence is available which allows for the comparison between cyber and non-cyber incidents of the same crime."

Justice secretary Michael Matheson said Police Scotland would recruit "civilian cyber specialists" to counter online crime.